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 (1.14.1) (judge verdict: Wrong Answer)

package main

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

const mod = 1000000007

// 1MB
const ioBufferSize = 1 * 1024 * 1024

var sc = func() *bufio.Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Buffer(make([]byte, ioBufferSize), ioBufferSize)
	sc.Split(bufio.ScanWords)
	return sc
}()

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

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

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

func main() {
	s := next()
	n := len(s) + 1
	left, right := make([]int, n), make([]int, n)

	for i := 0; i < n-1; i++ {
		c := s[i]
		if c == '<' {
			left[i+1] = left[i] + 1
		}
	}
	for i := n - 2; i > 0; i-- {
		c := s[i]
		if c == '>' {
			right[i] = right[i+1] + 1
		}
	}

	res := 0
	for i := 0; i < n; i++ {
		res += max(left[i], right[i])
	}

	fmt.Println(res)
}