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 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int main(void){
  char s[5*100000];
  long long len;
  long long i,k;
  scanf("%s",s);
  len=strlen(s);
  long long a[len+1];
  long long min;
  long long ans=0;
  a[0]=0;
  for(i=0;i<len;i++){
    if(s[i]=='<'){
      a[i+1]=a[i]+1;
    }
    else if(a[i]>0&&s[i]=='>'){
      a[i+1]=0;
    }
    else{
      a[i+1]=a[i]-1;
    }
    //printf("a[%d]=%d\n",i,a[i]);
  }
  //printf("a[%d]=%d\n",len,a[len]);
  min=a[0];
  for(i=0;i<len+1;i++){
    if(a[i]<min){
      min=a[i];
    }
  }
  if(min<0){
    min=-min;
    for(i=0;i<len+1;i++){
      a[i]=a[i]+min;

    }
    for(i=0;i<len+1;i++){
    if(a[i]<a[i+1]&&a[i]-min>=0){
      a[i]=a[i]-min;
    }
  //  printf("a[%d]=%d\n",i,a[i]);

      ans=ans+a[i];
    }
  }
  else{
    for(i=0;i<len+1;i++){
      ans=ans+a[i];
    }
  }
  //ans=ans-a[0];
  printf("%lld",ans);


  return 0;
}