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 <bits/stdc++.h>
using namespace std;
using ll=long long;
const int MOD=1000000007;

int main() {
  string s;
  cin >> s;
  queue<ll> q;
  ll count=1;
  if(s.size()==1){
    cout << 1 << endl;
    return 0;
  }
  for(ll i=0;i<s.size()-1;i++){
    if(s.at(i)==s.at(i+1)){
      count++;
    }
    else{
      q.push(count);
      count=1;
    }
  }
  q.push(count);
  ll ans=0;
  while(q.size()>1){
    ll f=q.front();
    q.pop();
    ll s=q.front();
    q.pop();
    if(f<s)
    ans=ans+((f-1)*f)/2+((s+1)*s)/2;
    else
    ans=ans+((f+1)*f)/2+((s-1)*s)/2;
  }
  if(!q.empty()){
    ll fr=q.front();
    ans=ans+((fr+1)*fr)/2;
  }
  cout << ans << endl;
}