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: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;
using System.IO;
using static System.Console;


namespace atcorder2
{
    class Program
    {
        public static long Read()
        {

            return long.Parse(Console.ReadLine());
        }

        public static long[] Reads()
        {

            return Console.ReadLine().Split().Select(long.Parse).ToArray();
        }

       




        static void Main(string[] args)
        {
            var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            Console.SetOut(sw);

            var s = ReadLine();
            var n = s.Length;
      
            long count = 0;
            long ans = 0;
            var right =new long[n+1];
            var left = new long[n+1];

            right[0] = 0;
            left[n] = 0;
            for (int i = 0; i <n; i++)
            {
                if (s[i] == '<') count++;
                else count = 0;
                right[i+1] = count;
            }
            count = 0;
            for (int i = n-1; i>=0; i--)
            {
                if (s[i] == '>') count++;
                else count = 0;
                left[i] = count;
            }
            for (int i = 0; i <= n; i++)
            {
                ans += Math.Max(right[i],left[i]);
            }
            
            
            WriteLine(ans);
            


            Console.Out.Flush();
        }
    }
}