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 (GCC 9.2.1) (judge verdict: Wrong Answer)

#include<stdio.h>

int main(){
  int buff;
  long ans=0;
  buff=getchar();
  while (buff!=EOF)
  {
    long lt=0,gt=0;
    if (buff=='<')
    {
      lt++;
      while ((buff=getchar())=='<'&&buff!=EOF){lt++;}
      if(buff=='>'){gt++;}
      while ((buff=getchar())=='>'&&buff!=EOF){gt++;}
      if (lt>=gt)
      {
        ans+=(lt*(lt+1))/2+(gt*(gt-1))/2;
      }else{
        ans+=(lt*(lt-1))/2+(gt*(gt+1))/2;
      }
    }else{
      gt++;
      while ((buff=getchar())=='>'&&buff!=EOF){gt++;}
      ans+=(gt*(gt+1))/2;
    }
  }
  
printf("%ld",ans);

  return 0;
}