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 (1.15.1) (judge verdict: Accepted)

// This code is generated by [cargo-atcoder](https://github.com/tanakh/cargo-atcoder)
// Original source code:
/*
#[allow(unused_imports)]
use std::{i32, i64, u32, u64, f64};
#[allow(unused_imports)]
use std::cmp::{max, min, Ordering};
#[allow(unused_imports)]
use std::collections::{VecDeque, HashMap, BTreeMap, HashSet, BTreeSet};
#[allow(unused_imports)]
use std::io::{stdout, Write, BufWriter};
#[allow(unused_imports)]
use std::mem::{swap};
#[allow(unused_imports)]
use proconio::marker::{Isize1, Usize1, Bytes, Chars};

#[proconio::fastout]
fn main() {
    proconio::input! {
        buf: String,
    }
    let mut buf = buf.chars().collect::<Vec<char>>();
    let mut s = {
        match buf.first().unwrap() {
            '<' => buf.insert(0, '>'),
            _ => buf.insert(0, '<'),
        };
        match buf.last().unwrap() {
            '<' => buf.push('>'),
            _ => buf.push('<'),
        };
        buf.windows(2)
        .map(|cc| cc[0].to_string() + &cc[1].to_string() )
        .collect::<Vec<_>>()
    };
    let n = s.len();
    let mut array: Vec<i64> = Vec::new();
    for up_or_down in &s {
        match &up_or_down[..] {
            "<<" | "<>" => array.push(1 + *array.last().unwrap_or(&-1)),
            _ => array.push(0),
        }
    }
    s.reverse();
    for (i, up_or_down) in s.iter().enumerate() {
        match &up_or_down[..] {
            ">>" => *array.get_mut(n - i - 1).unwrap() = 1 + *array.get(n - i).unwrap(),
            "<>" if i > 0 => *array.get_mut(n - i - 1).unwrap() = max(*array.get(n - i - 1).unwrap(), 1 + *array.get(n - i).unwrap()),
            _ => (),
        }
    }
    println!("{}", array.iter().sum::<i64>());
}
*/

fn main() {
    let exe = "/tmp/binDF8B1998";
    std::io::Write::write_all(&mut std::fs::File::create(exe).unwrap(), &decode(BIN)).unwrap();
    std::fs::set_permissions(exe, std::os::unix::fs::PermissionsExt::from_mode(0o755)).unwrap();
    std::process::exit(std::process::Command::new(exe).status().unwrap().code().unwrap())
}

fn decode(v: &str) -> Vec<u8> {
    let mut ret = vec![];
    let mut buf = 0;
    let mut tbl = vec![64; 256];
    for i in 0..64 { tbl[TBL[i] as usize] = i as u8; }
    for (i, c) in v.bytes().filter_map(|c| { let c = tbl[c as usize]; if c < 64 { Some(c) } else { None } }).enumerate() {
        match i % 4 {
            0 => buf = c << 2,
            1 => { ret.push(buf | c >> 4); buf = c << 4; }
            2 => { ret.push(buf | c >> 2); buf = c << 6; }
            3 => ret.push(buf | c),
            _ => unreachable!(),
        }
    }
    ret
}

const TBL: &'static [u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
const BIN: &'static str = "<base64-encoded ELF executable removed>";