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 Go (1.6) (judge verdict: Wrong Answer)

package main

import (
    "bufio"
    "fmt"
    "os"
    "strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func main() {
    sc.Split(bufio.ScanWords)

    s := readString()
    ans := make([]int, len(s) + 1)

    for i, c := range s {
        if c == '<' {
            ans[i+1] = ans[i] + 1
        }
    }

    for i := range s {
        i = len(s) - i - 1
        c := s[i]
        if c == '>' {
            ans[i] = max(ans[i], ans[i+1] + 1)
        }
    }

    var sum int64 = 0
    for _, e := range ans {
        sum += int64(e)
    }

    fmt.Println(sum)
}

func readInt() int {
    sc.Scan()
    n, _ := strconv.Atoi(sc.Text())
    return n
}

func readString() string {
    sc.Scan()
    return sc.Text()
}

func max(a, b int) int {
    if a > b {
        return a
    } else {
        return b
    }
}