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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
#include <queue>
#include <deque>
#include <bitset>
#include <iterator>
#include <list>
#include <stack>
#include <map>
#include <set>
#include <functional>
#include <numeric>
#include <utility>
#include <limits>
#include <iomanip>
#include <time.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>

using namespace std;
 
#define ull unsigned long long
#define ll long long
#define mod 1000000007
#define fi first
#define se second
#define pb push_back
#define mkp make_pair
#define PI acos(-1.0)
const int N=5e5 + 5;
const int M=1e5 + 5;

char s[N]; 
 
int main()
{
    ios_base::sync_with_stdio(false);
    int i,n;
    vector <int> v;
    cin>>s;
    n=strlen(s);
    ll arr[N];
    ll val = 0;
    //cout << n << endl;
    for(i=0;i<n;i++){
        if(s[i]=='<'){
            arr[i]=val;
            val++;
        }
        else{
            val=0;
        }
    }
    if(s[n-1]=='<'){
        arr[n]=val;
    }
    val=0;
    for(i=n-1;i>=0;i--){
        if(s[i]=='>'){
            arr[i+1]=val;
            val++;
        }
        else{
            if(s[i+1]=='>')
            arr[i+1]=max(val,arr[i]+1);
            val=0;
        }
    }
    if(s[0]=='>'){
        arr[0]=val;
    }
    ll foo = 0;
    // for(i=0;i<=n;i++){
    //     cout << arr[i] << " ";
    // }
    // cout << endl;
    for(i=0;i<=n;i++) foo += arr[i];
    cout << foo << endl;



    return 0;
}