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()
t = s.split(">")
t2 = s.split("<")
a = []
b = []
for i in t:
    if i != '':
        a.append(i)

for i in t2:
    if i != '':
        b.append(i)
n = len(a)
n2 = len(b)
if len(b) == 1 and len(a) == 1:
    if s[0] == '>':
        y = len(b[0])
        x = len(a[0])
        sums = 0
        sums += (x * (x + 1)) / 2
        sums += (y * (y + 1)) / 2
        print(int(sums))
        exit()

tmp = min(n, n2)
sums = 0
if n2 > n:
    for i in range(tmp):
        x = len(a[i])
        y = len(b[i+1])
        if x > y:
            sums += (x * (x + 1)) / 2
            sums += (y * (y - 1)) / 2
        else:
            sums += (x * (x - 1)) / 2
            sums += (y * (y + 1)) / 2
elif n > n2:
    for i in range(tmp):
        x = len(a[i])
        y = len(b[i])
        if x > y:
            sums += (x * (x + 1)) / 2
            sums += (y * (y - 1)) / 2
        else:
            sums += (x * (x - 1)) / 2
            sums += (y * (y + 1)) / 2
elif n == n2:
    for i in range(tmp):
        x = len(a[i])
        y = len(b[i])
        if x > y:
            sums += (x * (x + 1)) / 2
            sums += (y * (y - 1)) / 2
        else:
            sums += (x * (x - 1)) / 2
            sums += (y * (y + 1)) / 2
if n > n2:
    x = len(a[n-1])
    sums += (x * (x + 1)) / 2
elif n2 > n:
    x = len(b[0])
    sums += (x * (x + 1)) / 2

print(int(sums))