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 <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <cmath>
#include <map>
#include <iomanip>
#define intt long long

intt func(intt n) {
	intt r = 0;
	while (n > 0) {
		r += n;
		--n;
	}
	return r;
}

int main() {
	std::string s; std::cin >> s;
	intt N = s.size();
	intt ans = 0;
	for (intt i = 0; i < N - 1; ++i) {
		if (s[i] == '<' && s[i + 1] == '>') {
			intt count1 = 0;
			intt count2 = 0;
			for (intt j = i; j >= 0; --j) {
				if (s[j] == '>')
					break;
				++count1;
			}
			for (intt j = i + 1; j < N; ++j) {
				if (s[j] == '<')
					break;
				++count2;
			}
			if (count1 > count2)
				ans += func(count1) + func(count2 - 1);
			else
				ans += func(count2) + func(count1 - 1);
		}
	}
	intt count3 = 0;
	for (intt i = N - 1; i >= 0; --i) {
		if (s[i] == '>')
			break;
		++count3;
	}
	ans += func(count3);
	std::cout << ans << std::endl;

}