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: Wrong Answer)

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
 
int main(){
  string a,x;
  int i;
  ll l,ans,pl;
  cin >> a;
  x=a.substr(0,1);
  a.erase(0,1);
  l=1;
  ans=0;
  pl=0;
  while(a.length()!=0){
    if((x==">")&(a.substr(0,1)=="<")){
      ans-=min(l,pl);
    }
    if(x==a.substr(0,1)){
      l+=1;
    }
    else{
      ans+=(l+1)*l/2;
      pl=l;
      x=a.substr(0,1);
      l=1;
    }
    a.erase(0,1);
  }
  ans+=(l+1)*l/2;
  cout << ans;
}