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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args: Array<String>) {
    val s = readLine()!!
    val n = s.length + 1
    val lw = Array(n - 1) {0}
    val gr = Array(n - 1) {0}
    for (i in s.indices) {
        if (s[i] == '<') {
            lw[i] = (if(i > 0) lw[i - 1] else 0) + 1
        }
    }
    for (i in s.length - 1 downTo 0) {
        if (s[i] == '>') {
            gr[i] = (if(i < n - 2) gr[i + 1] else 0) + 1
        }
    }

    println((0 until n).map {
        Math.max(
            if (it > 0) lw[it - 1].toLong() else 0L,
            if (it < n - 1) gr[it].toLong() else 0L)
    }.sum())
}