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 (2.4.0) (judge verdict: Wrong Answer)

# ><
si = lambda: input()
ni = lambda: int(input())
nm = lambda: map(int, input().split())
nl = lambda: list(map(int, input().split()))

S = si()
L = []
t = 1
t_str = ''
for i in range(len(S)-1):
    if i == 0:
        t = 1
        t_str = S[i]

    if t_str == S[i] and S[i]==S[i+1]:
        t += 1
    else:
        L.append(t)
        t = 1
        t_str = S[i+1]
    
    if i == len(S)-2:
        L.append(t)

# print(L)
odd = 0
even = 0
for i in range(len(L)):
    if i%2 == 0:
        odd = 0
        even = 0

        odd = L[i]
    
    if i%2 == 1:
        even = L[i]
        if odd < even:
            L[i-1] -= 1
        elif odd > even:
            L[i] -= 1
# print(L)
ans = 0
for i in range(len(L)):
    l = L[i]
    ans += (l*(l+1))/2
print(int(ans))