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 C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;

namespace _20191103
{
    class Program
    {
        static void Main(string[] args)
        {
            String str = Console.ReadLine();
            //String str = "<>>><<><<<<<>>><";
            int[] nums = new int[str.Length+1];
            for (int i = 0; i < nums.Length; i++) {
                nums[i] = 0;
            }
            int cnt = 0;
            for (int i = 0; i < str.Length; i++) {
                if (str[i] == '<') {
                    nums[i+1] = nums[i] + 1;
                    cnt = 0;
                }
                else {
                    nums[i+1] = 0;
                    cnt+=1;
                    if (nums[i] <= nums[i+1]) {
                        for (int j = 0; j < cnt; j++) {
                            if (nums[i-j] <= nums[i-j+1]) {
                                nums[i-j]++;
                            }
                        }
                    }
                }
                //Console.Write("i= " + i + ", cnt= " + cnt + ", Arry= ");
                //printArray(nums);
            }
            /*for (int j = 0; j < str.Length; j++) {
                for (int i = 0; i < str.Length; i++) {
                    if (str[i] == '<') {
                        if (nums[i] >= nums[i+1]) {
                            nums[i+1] = nums[i] + 1;
                        }
                    }
                    else {
                        if (nums[i] <= nums[i+1]) {
                            nums[i] = nums[i+1] + 1;
                        }
                    }
                }
            }*/
            int ans = 0;
            foreach (int num in nums) {
                ans += num;
            }
            Console.WriteLine(ans);
            //printArray(nums);
        }

        static void printArray(int[] arr) {
            for (int i = 0; i < arr.Length; i++) {
                Console.Write(arr[i] + ", ");
            }
            Console.WriteLine();
        }
    }
}