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 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>

int max(int x, int y) {
	if (x < y) {
		return y;
	} else {
		return x;
	}
}

int main(void) {
	long long ans = 0;
	char c[500000];
	int s[500000] = {0};
	c[0] = getchar();
	s[0] = 1;
	int i = 0, d;
	while ((d = getchar()) != EOF) {
		if (d != c[i]) {
			c[++i] = d;
		}
		s[i]++;
	}
	i++;
	int *t = s;
	if (c[i - 1] == '<') {
		ans += (s[i - 1] + 1) * s[i - 1] / 2;
		i--;
	}
	if (c[0] == '>') {
		ans += (s[0] + 1) * s[0] / 2;
		t++;
		i--;
	}
	for (int j = 0; j < i; j += 2) {
		ans += (t[j] - 1) * t[j] / 2;
		ans += (t[j + 1] - 1) * t[j + 1] / 2;
		ans += max(t[j], t[j + 1]);
	}
	printf("%lld\n", ans);
	return 0;
}