diff --git a/atcoder/abc353/a.rs b/atcoder/abc353/a.rs
new file mode 100644
index 00000000..a27e50ab
--- /dev/null
+++ b/atcoder/abc353/a.rs
@@ -0,0 +1,37 @@
+use std::io::Read;
+
+fn get_word() -> String {
+    let stdin = std::io::stdin();
+    let mut stdin=stdin.lock();
+    let mut u8b: [u8; 1] = [0];
+    loop {
+        let mut buf: Vec<u8> = Vec::with_capacity(16);
+        loop {
+            let res = stdin.read(&mut u8b);
+            if res.unwrap_or(0) == 0 || u8b[0] <= b' ' {
+                break;
+            } else {
+                buf.push(u8b[0]);
+            }
+        }
+        if buf.len() >= 1 {
+            let ret = String::from_utf8(buf).unwrap();
+            return ret;
+        }
+    }
+}
+
+fn get<T: std::str::FromStr>() -> T { get_word().parse().ok().unwrap() }
+
+fn main() {
+    let n: i32 = get();
+    let h1: i32 = get();
+    for i in 2..=n {
+        let x: i32 = get();
+        if x > h1 {
+            println!("{}", i);
+            return;
+        }
+    }
+    println!("-1");
+}
diff --git a/atcoder/abc353/b.rs b/atcoder/abc353/b.rs
new file mode 100644
index 00000000..6f894bfd
--- /dev/null
+++ b/atcoder/abc353/b.rs
@@ -0,0 +1,41 @@
+use std::io::Read;
+
+fn get_word() -> String {
+    let stdin = std::io::stdin();
+    let mut stdin=stdin.lock();
+    let mut u8b: [u8; 1] = [0];
+    loop {
+        let mut buf: Vec<u8> = Vec::with_capacity(16);
+        loop {
+            let res = stdin.read(&mut u8b);
+            if res.unwrap_or(0) == 0 || u8b[0] <= b' ' {
+                break;
+            } else {
+                buf.push(u8b[0]);
+            }
+        }
+        if buf.len() >= 1 {
+            let ret = String::from_utf8(buf).unwrap();
+            return ret;
+        }
+    }
+}
+
+fn get<T: std::str::FromStr>() -> T { get_word().parse().ok().unwrap() }
+
+fn main() {
+    let n: i32 = get();
+    let k: i32 = get();
+    let mut rem = k;
+    let mut ans = 0;
+    for _ in 0..n {
+        let a: i32 = get();
+        if rem < a {
+            ans += 1;
+            rem = k - a;
+        } else {
+            rem -= a;
+        }
+    }
+    println!("{}", ans + 1);
+}
diff --git a/atcoder/abc353/c.rs b/atcoder/abc353/c.rs
new file mode 100644
index 00000000..dc899c79
--- /dev/null
+++ b/atcoder/abc353/c.rs
@@ -0,0 +1,82 @@
+// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
+macro_rules! input {
+    ($($r:tt)*) => {
+        let stdin = std::io::stdin();
+        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
+        let mut next = move || -> String{
+            bytes.by_ref().map(|r|r.unwrap() as char)
+                .skip_while(|c|c.is_whitespace())
+                .take_while(|c|!c.is_whitespace())
+                .collect()
+        };
+        input_inner!{next, $($r)*}
+    };
+}
+
+macro_rules! input_inner {
+    ($next:expr) => {};
+    ($next:expr,) => {};
+    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
+        let $var = read_value!($next, $t);
+        input_inner!{$next $($r)*}
+    };
+}
+
+macro_rules! read_value {
+    ($next:expr, [ $t:tt ; $len:expr ]) => {
+        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
+    };
+    ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));
+}
+
+trait Bisect<T> {
+    fn lower_bound(&self, val: &T) -> usize;
+    fn upper_bound(&self, val: &T) -> usize;
+}
+
+impl<T: Ord> Bisect<T> for [T] {
+    fn lower_bound(&self, val: &T) -> usize {
+        let mut pass = self.len() + 1;
+        let mut fail = 0;
+        while pass - fail > 1 {
+            let mid = (pass + fail) / 2;
+            if &self[mid - 1] >= val {
+                pass = mid;
+            } else {
+                fail = mid;
+            }
+        }
+        pass - 1
+    }
+    fn upper_bound(&self, val: &T) -> usize {
+        let mut pass = self.len() + 1;
+        let mut fail = 0;
+        while pass - fail > 1 {
+            let mid = (pass + fail) / 2;
+            if &self[mid - 1] > val {
+                pass = mid;
+            } else {
+                fail = mid;
+            }
+        }
+        pass - 1
+    }
+}
+
+fn main() {
+    input! {
+        n: usize,
+        a: [i64; n],
+    }
+    let mut sum: i64 = a.iter().sum();
+    sum *= n as i64 - 1;
+    const MOD: i64 = 100_000_000;
+    let mut a = a;
+    a.sort();
+    for i in 0..n {
+        let val = a[i];
+        let idx = a.lower_bound(&(MOD - val));
+        sum -= MOD * (n - idx.max(i + 1)) as i64;
+    }
+    println!("{}", sum);
+}
diff --git a/atcoder/abc353/d.rs b/atcoder/abc353/d.rs
new file mode 100644
index 00000000..8b91397c
--- /dev/null
+++ b/atcoder/abc353/d.rs
@@ -0,0 +1,51 @@
+// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
+macro_rules! input {
+    ($($r:tt)*) => {
+        let stdin = std::io::stdin();
+        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
+        let mut next = move || -> String{
+            bytes.by_ref().map(|r|r.unwrap() as char)
+                .skip_while(|c|c.is_whitespace())
+                .take_while(|c|!c.is_whitespace())
+                .collect()
+        };
+        input_inner!{next, $($r)*}
+    };
+}
+
+macro_rules! input_inner {
+    ($next:expr) => {};
+    ($next:expr,) => {};
+    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
+        let $var = read_value!($next, $t);
+        input_inner!{$next $($r)*}
+    };
+}
+
+macro_rules! read_value {
+    ($next:expr, [ $t:tt ; $len:expr ]) => {
+        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
+    };
+    ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));
+}
+
+fn main() {
+    input! {
+        n: usize,
+        a: [i64; n],
+    }
+    let mut sum = 0;
+    const MOD: i64 = 998_244_353;
+    let mut coef = 0;
+    for i in (0..n).rev() {
+        sum += a[i] * i as i64;
+        sum += a[i] * coef;
+        sum %= MOD;
+        let mut d = 1;
+        while d <= a[i] {
+            d *= 10;
+        }
+        coef = (coef + d) % MOD;
+    }
+    println!("{}", sum);
+}
diff --git a/atcoder/abc353/e.rs b/atcoder/abc353/e.rs
new file mode 100644
index 00000000..9c6f3603
--- /dev/null
+++ b/atcoder/abc353/e.rs
@@ -0,0 +1,87 @@
+// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
+macro_rules! input {
+    ($($r:tt)*) => {
+        let stdin = std::io::stdin();
+        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
+        let mut next = move || -> String{
+            bytes.by_ref().map(|r|r.unwrap() as char)
+                .skip_while(|c|c.is_whitespace())
+                .take_while(|c|!c.is_whitespace())
+                .collect()
+        };
+        input_inner!{next, $($r)*}
+    };
+}
+
+macro_rules! input_inner {
+    ($next:expr) => {};
+    ($next:expr,) => {};
+    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
+        let $var = read_value!($next, $t);
+        input_inner!{$next $($r)*}
+    };
+}
+
+macro_rules! read_value {
+    ($next:expr, [ $t:tt ; $len:expr ]) => {
+        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
+    };
+    ($next:expr, chars) => {
+        read_value!($next, String).chars().collect::<Vec<char>>()
+    };
+    ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));
+}
+
+fn main() {
+    // In order to avoid potential stack overflow, spawn a new thread.
+    let stack_size = 104_857_600; // 100 MB
+    let thd = std::thread::Builder::new().stack_size(stack_size);
+    thd.spawn(|| solve()).unwrap().join().unwrap();
+}
+
+fn rec(s: &[Vec<char>], pos: usize) -> i64 {
+    let n = s.len();
+    if n == 0 {
+        return 0;
+    }
+    let mut ans = 0;
+    let mut pass = s.len() + 1;
+    let mut fail = 0;
+    while pass - fail > 1 {
+        let mid = (pass + fail) / 2;
+        if s[mid - 1].len() <= pos {
+            fail = mid;
+        } else {
+            pass = mid;
+        }
+    }
+    let mut last = pass - 1;
+    for c in 'a'..='z' {
+        let mut pass = s.len() + 1;
+        let mut fail = last;
+        while pass - fail > 1 {
+            let mid = (pass + fail) / 2;
+            if s[mid - 1].len() <= pos || s[mid - 1][pos] <= c {
+                fail = mid;
+            } else {
+                pass = mid;
+            }
+        }
+        ans += rec(&s[last..pass - 1], pos + 1);
+        let len = (pass - last - 1) as i64;
+        ans += len * (len - 1) / 2;
+        last = pass - 1;
+    }
+    ans
+}
+
+// Tags: trie-less
+fn solve() {
+    input! {
+        n: usize,
+        s: [chars; n],
+    }
+    let mut s = s;
+    s.sort();
+    println!("{}", rec(&s, 0));
+}
diff --git a/atcoder/abc353/remain.txt b/atcoder/abc353/remain.txt
new file mode 100644
index 00000000..ab713757
--- /dev/null
+++ b/atcoder/abc353/remain.txt
@@ -0,0 +1,2 @@
+f
+g