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 <bits/stdc++.h>
using namespace std;

int main(){
	string s;
	
	int tmp = 0;
	
	long int N;
	
	long int aux = 1;
	long int men = 1;
	
	//vector <long int> v(N);
	long int sum = 0;
	
	cin >> s;
	
	N = s.length() + 1;
	
	for(long int i = 0; i < N-1; i++){
		if(s[i] == s[i+1] && s[i] == '>'){
			aux++;
			continue;
		} else if(s[i] == '>'){
			sum += (aux*(aux - 1))/2;
			
			sum += max(men, aux);
			men = 1;
			aux = 1;
			continue;
		}
		
		if(s[i] == s[i+1] && s[i] == '<'){
			men++;
			continue;
		} else if(s[i] == '<'){
			sum += (men*(men - 1))/2;
			
			if(i == N-2){
				sum += men;
			}
			continue;
		}
	}	
	
	
	cout << sum << endl;
	return 0;	
}