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 Python (3.4.3) (judge verdict: Wrong Answer)

s = input()
for_l = [0] * (len(s) + 1)
for_r = [0] * (len(s) + 1)
l = [0] * (len(s) + 1)
for i in range(1, len(for_l)):
    if s[i - 1] == "<":
        for_l[i] = for_l[i - 1] + 1
    else:
        for_l[i] = 0
for i in range(1, len(for_l)):
    if s[-i] == ">":
        for_r[-i-1] = for_r[-i] + 1
    else:
        for_r[i] = 0
for i in range(len(for_l)):
    l[i] = max(for_l[i], for_r[i])
print(sum(l))