Problem:
Score : 300 points

Problem Statement

Given is a string S of length N-1.
Each character in S is < or >.

A sequence of N non-negative integers, a_1,a_2,\cdots,a_N, is said to be good when the following condition is satisfied for all i (1 \leq i \leq N-1):

If S_i= <: a_i<a_{i+1}

If S_i= >: a_i>a_{i+1}

Find the minimum possible sum of the elements of a good sequence of N non-negative integers.

Constraints

2 \leq N \leq 5 \times 10^5

S is a string of length N-1 consisting of < and >.

Input

Input is given from Standard Input in the following format:

S

Output

Find the minimum possible sum of the elements of a good sequence of N non-negative integers.

Sample Input 1

<>>

Sample Output 1

3

a=(0,2,1,0) is a good sequence whose sum is 3.
There is no good sequence whose sum is less than 3.

Sample Input 2

<>>><<><<<<<>>><

Sample Output 2

28

Solution in Rust (1.42.0) (judge verdict: Accepted)

use proconio::input;

use std::io::{stdout, Write, BufWriter};

fn main() {
    let out = stdout();
    let mut out = BufWriter::new(out.lock());

    input! {s: String}
    let s_u8_vec = s.as_bytes();
    let left_small = "<".as_bytes()[0];
    let mut a:Vec<usize> = Vec::new();
    a.resize(s_u8_vec.len() + 1, 0);
    let mut symbol_count:usize = 0;
    for i in 0..=s_u8_vec.len() {
        if i < s_u8_vec.len() && s_u8_vec[i] == left_small {
            a[i] = symbol_count;
            symbol_count += 1;
        } else if symbol_count > 0 {
            a[i] = symbol_count;
            symbol_count = 0;
        }
    }
    symbol_count = 0;
    for i in (0..=s_u8_vec.len()).rev() {
        if i > 0 && s_u8_vec[i - 1] != left_small {
            a[i] = symbol_count;
            symbol_count += 1;
        } else if symbol_count > 0 {
            a[i] = symbol_count.max(a[i]);
            symbol_count = 0;
        }
    }
    writeln!(out, "{}", a.iter().sum::<usize>()).unwrap();
}