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 (3.8.2) (judge verdict: Wrong Answer)

s=input()
#><となるところを見つける<<となるところを見つける>>となるところを見つける<>となるところについて考える
n=len(s)
ans=[0]*(n+1)
if s[0]=='<':
    ans[0]=0
if s[n-1]=='>':
    ans[n]=0
for i in range(n-2):
    if s[i]=='>' and s[i+1]=='<':
        ans[i+1]=0

#左から>>となる部分を探す
for i in range(n):
    if s[i]=='<':
        ans[i+1]=max(ans[i+1],ans[i]+1)
for i in range(n-1,0,-1):
    if s[i]=='>':
        ans[i]=max(ans[i],ans[i+1]+1)
print(sum(ans))