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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <numeric>
#include <vector>
using namespace std;

#define int long


 signed main(){
  string s;
  cin >> s;
  int n = s.size()+1;
//  int *a;
//  a = (int *)malloc(n*sizeof(int));
  int a[n];
  //vector<int> a(n,0);

  int cnt=0;
  for(int i=0; i<n;i++){
    if(s[i] == '<'){
      a[i] = cnt;
      cnt++;
    }else{
      a[i]=cnt;
      cnt=0;
    }
  }
  cnt=0;
  for(int i=n-1;i>=0;i--){
    if(s[i] == '>'){
      cnt++;
      a[i] = max(a[i],cnt);
    }else{
      cnt =0;
      a[i] = max(a[i],cnt);
    }
  }
  int ans=0;
  for(int i=0; i< n; i++){
    ans += a[i];
  }
  //cout << "\n" << ans << endl;
  cout << ans;
  return 0;
}