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: Accepted)

S = list(input())
L = len(S)
count = 0
count_minus = [0] * L
for i in range(L):
    if S[i] == ">":
        count = 0
    else:
        count += 1
    count_minus[i] = count

count = 0
count_plus = [0] * L
for i in reversed(range(L)):
    if S[i] == "<":
        count = 0
    else:
        count += 1
    count_plus[i] = count

result_list = [0] * (L-1)
for i in range(len(result_list)):
    result_list[i] = max(count_minus[i], count_plus[i+1])

result = sum(result_list) + count_minus[L-1] + count_plus[0] 
print(result)