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 Julia (0.5.0) (judge verdict: Accepted)

S=chomp(readline())
N=length(S)
id=1
ans=0
while id<=N
	L=R=0
	while id<=N&&S[id]=='<'
		id+=1
		L+=1
	end
	while id<=N&&S[id]=='>'
		id+=1
		R+=1
	end
	ans+=div(L*(L+1),2)+div(R*(R+1),2)-min(L,R)
end
println(ans)