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 Java (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);

		char[] input = sc.next().toCharArray();

		int n = input.length + 1;
		int a[] = new int[n];

		for(int i = 1; i < n; i++){
			if(input[i - 1] == '<'){
				a[i] = a[i - 1] + 1;
			}
			else {
				a[i] = 0;
			}
		}

		for(int i = n - 2; i >= 0; i--){
			if(input[i] == '>'){
				a[i] = Math.max(a[i], a[i + 1] + 1);
			}
		}

		long sum = 0;
		for(int i = 0; i < n; i++){
//			System.out.println(a[i]);
			sum += a[i];
		}

		System.out.println(sum);
	}

}