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 (GCC 9.2.1) (judge verdict: Accepted)

#include <stdio.h>
#include <string.h>
int main(void){
    char c[1000000]={};
    gets(c);
    long int sum=0;
    long int leftM=0;
    long int rightM=0;
    for(int i=0;i<strlen(c)+1;i++){
        
        
        if(c[i-1]=='<' && c[i-2]=='<'){
            leftM++;
        }else{
            leftM=0;
            for(int j=1;i-j>=0 && c[i-j]=='<';j++)leftM++;
        }
        
        if(c[i]=='>' && c[i-1]=='>'){
            rightM--;
        }else{
            rightM=0;
            for(int j=0;i+j<=strlen(c) && c[i+j]=='>';j++)rightM++;
        }
        //printf("%d ,%d %d \n",i,leftM, rightM);   
        
        (leftM>=rightM)?(sum+=leftM):(sum+=rightM);
    }
    printf("%ld\n",sum);
}