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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		String str = sc.next();
		String[] array = str.split("");

		String before = "";
		int smcount = 0;
		int grcount = 0;
		long ans = 0;

		for (int i = 0; i < array.length; i++) {

			String tmp = array[i];

			if (tmp.equals("<")) {
				if (before.equals(tmp)) {
					smcount++;
				} else {
					long sum = getArraySum(grcount, smcount);
					ans = ans + sum;
					smcount = 1;
					grcount = 0;
				}

			} else {
				if (before.equals(tmp)) {
					grcount++;
				} else {
					grcount = 1;
				}
			}
			before = array[i];
		}
		long sum = getArraySum(grcount, smcount);
		ans = ans + sum;
		System.out.println(ans);

	}

	private static long getArraySum(int a, int b) {
		long large = a > b ? a : b;
		long small = a < b ? a : b;

		small--;

		long lsum = large * (large + 1) / 2;
		long ssum = small * (small + 1) / 2;

		long sum = lsum + ssum;

		return sum;

	}

}