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# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.IO;
using System.Linq;

namespace AGC040
{
    class A
    {
        static void Main(string[] args)
        {
            //StreamReader sr = new StreamReader(@"test");
            string S = Console.ReadLine();
            //string S = sr.ReadLine();
            int[] res = new int[S.Length + 1];
            int index = 1;
            for (int i = 0; i < S.Length; i++)
            {
                if (S[i] == '<') { res[i + 1] = index; index++; }
                else { index = 1; }
            }

            index = 1;
            for (int i = S.Length - 1; i >= 0; i--)
            {
                if (S[i] == '>') { res[i] = Math.Max(res[i], index); index++; }
                else { index = 1; }
            }

            int sum = 0;
            for (int i = 0; i < S.Length + 1; i++)
            {
                sum += res[i];
            }

            Console.WriteLine(sum);

        }
    }
}