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;

int main(){
  string S;
  cin >> S;
  vector<long long> c(S.size()+1, 0);
  for (int i=0; i<S.size(); i++) {
    if ((S.at(i) == '<') && (c.at(i) >= c.at(i+1))) {
      c.at(i+1) = c.at(i)+1;
    }
  }
  for (int i=S.size()-1; i>=0; i--) {
    if ((S.at(i) == '>') && (c.at(i) <= c.at(i+1))) {
      c.at(i) = c.at(i+1)+1;
    }
  }
  int sum = 0;
  for (int i=0; i<c.size(); i++) {
    sum += c.at(i);
  }
  cout << sum << endl;
}