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 Perl (v5.18.2) (judge verdict: Wrong Answer)

chomp($line = <>);
@s = split(//, $line);

for $i (1 .. $#s){
	if($i == 1){
		if(($s[$i] eq '<') and ($s[$i - 1] eq '>')){
			$r = 1;
			$now = 0;
		}else{
			$r = 1;
			$now = 1;
		}
	}else{
		if(($s[$i] eq '>') and ($s[$i - 1] eq '<')){
			$now++;
			$r += $now;
			$now = 0;
		}elsif(($s[$i] eq '<') and ($s[$i - 1] eq '>')){
			$now = 0;
		}else{
			$now++;
			$r += $now;
		}
	}
}

if($s[$#s] eq '<'){
	$now++;
	$r += $now;
}

print "$r\n";