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"

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define REP(i, n) for (int i = 1; i <= (int)(n); i++)
#define all(v) v.begin(), v.end()
using namespace std;
using ll = long long;
using pi = pair<int, int>;
const ll INF = 1LL << 60;

int main() {
	string s;
	cin >> s;
	vector<ll>arr(s.size() + 1);
	rep(i, s.size() + 1) {
		if (i == 0)arr[i] = (s[i] == '<') ? 0 : 1;
		else if (i == s.size())arr[i] = (s[i-1] == '>') ? 0 : arr[i - 1] +1;
		else {
			if (s[i - 1] == '>' && s[i] == '<')arr[i] = 0;
			else if (s[i - 1] == '<')arr[i] = arr[i - 1] + 1;
			else arr[i] = 0;
		}
	}

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

	ll sum = accumulate(all(arr),0);
	cout << sum << endl;
}