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: Wrong Answer)

import java.util.*

fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    val s = sc.next()
    println(problemagc040(s))
}

fun problemagc040(s: String): Int {
    var prev = s[0]
    val list = mutableListOf(prev to 1)
    for (i in 1 until s.length) {
        val si = s[i]
        if (si == prev) {
            val last = list[list.size - 1]
            list[list.size - 1] = last.copy(si, last.second + 1)
        } else {
//            debugLog("prev:si", prev, si, list[list.size - 1])
            list.add(si to 1)
        }
        prev = si
    }
//    debugLog(list)
    var sum = 0
    for (i in 0 until list.size) {
        val pair = list[i]
        var num = if (i != 0 && i != 1 && pair.first == '>' && list[i - 1].first == '<') {
            (0 until pair.second).sum()
        } else {
            (0..pair.second).sum()
        }
        if (pair.second == 1) num = 0
        sum += num
//        debugLog(num)
    }
    if (list.size >= 2) {
        val last = list[list.size - 1]
        if (last != list[list.size - 2]) {
            if (last.first == '<') sum += if (last.second == 1) 1 else last.second + 1
        }
    }
    return sum
}