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 C# (.NET Core 3.1.201) (judge verdict: Wrong Answer)

using System;
using System.Text;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using E = System.Linq.Enumerable;
class Program
{
    static char[] abc = "abcdefghijklmnopqrstuvwxyz".ToCharArray();
    static long mod = 1000000007;
    static void Main(string[] args)
    {

        //var NM = Console.ReadLine().Split(' ').Select(x => long.Parse(x)).ToArray();
        var S = Console.ReadLine();
        long N = S.Length;

        var L = S[0];
        long ans = 0;
        long pre = 0;
        for (int i = 0; i < N; i++)
        {
            var now = S[i];
            var count = 1;

            while (i + 1 < N && now == S[i + 1])
            {
                count++;
                i++;
            }
            ans += count * (count + 1) / 2;
            if (S[i] == '>') ans -= Math.Min(count, pre);
            pre = count;
        }
        
        Console.WriteLine(ans);
    }



}