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;
	cin>>s;
	vector<int> arr(s.size()+1,0);
	for(int i=0;i<s.size();i++){
		if(s[i]=='<')
			arr[i+1]= arr[i]+1;
	}
	

	for(int i=s.size()-1;i>=0;i--){
		if(s[i]=='>')
			if(arr[i]<=arr[i+1])
				arr[i] =arr[i+1]+1;
	}
	long long sum=0;

	for(int i=0;i<arr.size();i++){
		
		sum+=arr[i];
	}
	cout<<sum<<endl;
	return 0;
}