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: Runtime Error)

using System;
class ProgramA
    {
        static void Main(string[] args)
        {
            
            string input = Console.ReadLine();
            int[] line = new int[1000000];
            int count = 1;
            int count_line = 0;
            int sum = 0;
            int start = 1;

            
            for(int i = 1; i < input.Length;i++)
            {
                if(input[i] == input[i -1])
                {
                    count++;
                }
                else
                {
                    line[count_line] = count;
                    count = 1;
                    count_line++;
                }
                if(i == input.Length - 1)
                {
                    line[count_line] = count;
                    count_line++;
                }
            }

            for(int i = 0;i < count_line;i++)
            {
                int plus = line[i] - 1;
                sum += (plus + 1) * plus / 2;
            }

            if(input[0] == '>')
            {
                start = 2;
                sum += line[0];
                if(count_line % 2 == 0)
                    sum += line[count_line - 1];
            }
            else
            {
                if(count_line % 2 == 1)
                    sum += line[count_line - 1];
            }

            for(int i = start;i < count_line;i = i + 2)
            {
                if(line[i] > line[i - 1])
                    sum += line[i];
                else
                    sum += line[i - 1];
            }
          
            Console.WriteLine(sum);
        }
    }