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 Fortran (gfortran v4.8.4) (judge verdict: Wrong Answer)

program main
  implicit none
  character(5*10**5) :: s
  integer ::  n, i, k, j, l, m, ans
  integer, allocatable :: a(:)

  read(*,*) s
  n = len_trim(s) + 1

  ans = 0
  do i = 1, n-1
     if(s(i:i) == '<') then
        k = i
     do j = 1, n-1
        if (s(j:j) == '>') then
           l = j
           exit
        end if
     end do

     do j = l, n-1
        if(s(j:j) == '<') then
           m = i
           exit
        end if
     end do

     if (l >= m) then
        ans = ans + l*(l+1)/2 + m*(m-1)/2
     else
        ans = ans + m*(m+1)/2 + l*(l-1)/2
     end if

  end if
end do

write(*,*) ans

stop
end program main