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 PyPy3 (7.3.0) (judge verdict: Accepted)

# https://atcoder.jp/contests/agc040/tasks/agc040_a
import sys
# sys.setrecursionlimit(100000)


def input():
    return sys.stdin.readline().strip()


def input_int():
    return int(input())


def input_int_list():
    return [int(i) for i in input().split()]


def main():
    S = input()
    ans = 0
    left = 0
    right = 0
    for i in range(len(S) - 1):
        if S[i] + S[i + 1] == "><":
            right += 1
            tmp = max(left, right)
            ans += tmp
            ans += sum([i for i in range(left)])
            ans += sum([i for i in range(right)])
            right = 0
            left = 0
        else:
            if S[i] == ">":
                right += 1
            elif S[i] == "<":
                left += 1
    else:
        if S[-1] == "<":
            left += 1
        else:
            right += 1
        tmp = max(left, right)
        ans += tmp
        ans += sum([i for i in range(left)])
        ans += sum([i for i in range(right)])
    print(ans)
    return


if __name__ == "__main__":
    main()