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)

/*
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 ░██   █▌▒▓█    ▄   ▒██ ██░▓██░ ██▓▒▒██▀▀██░▒███   ▓██ ░▄█ ▒
 ░▓█▄   ▌▒▓▓▄ ▄██▒  ░ ▐██▓░▒██▄█▓▒ ▒░▓█ ░██ ▒▓█  ▄ ▒██▀▀█▄
 ░▒████▓ ▒ ▓███▀ ░  ░ ██▒▓░▒██▒ ░  ░░▓█▒░██▓░▒████▒░██▓ ▒██▒
  ▒▒▓  ▒ ░ ░▒ ▒  ░   ██▒▒▒ ▒▓▒░ ░  ░ ▒ ░░▒░▒░░ ▒░ ░░ ▒▓ ░▒▓░
  ░ ▒  ▒   ░  ▒    ▓██ ░▒░ ░▒ ░      ▒ ░▒░ ░ ░ ░  ░  ░▒ ░ ▒░
  ░ ░  ░ ░         ▒ ▒ ░░  ░░        ░  ░░ ░   ░     ░░   ░
    ░    ░ ░       ░ ░               ░  ░  ░   ░  ░   ░
  ░      ░         ░ ░
*/
//focus less on how much problem you should solve within a fixed time and focus more on getting the problem solved and
//learning something from it
#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define rep(i,a,b) for(ll i=a; i<b; i++)
#define per(i,a,b) for(ll i=a; i>=b; i--)
#define ll long long int
#define ld long double
#define vi vector<ll>
#define vii vector <pair<ll,ll> >
#define sedes set <ll, greater <ll> >
#define seasc set <ll>
#define pb push_back
#define mkp make_pair
#define ff first
#define ss second
#define MOD 1000000007
#define prec(n) fixed<<setprecision(n)
#define maxpq priority_queue<int>
#define minpq priority_queue<int, vector<int>, greater<int> >
#define umap unordered_map<ll, ll>
#define map map<ll, ll>
#define autoit(x,it) for(auto it = x.begin(); it != x.end(); it++)
#define mems(a, i) memset(a, i, sizeof(a))
#define endl '\n'
#define all(v) v.begin(),v.end()
#define gcd(a,b) __gcd((a),(b))
#define lcm(a,b) ((a)*(b))/gcd((a),(b))
#define deba(a) cout << #a << " " <<a << endl;
int main()
{
	fast;
#ifndef ONLINE_JUDGE
	freopen("D:\\input.txt", "r", stdin);
	freopen("D:\\output.txt", "w", stdout);
#endif
	int t = 1;
	// cin >> t;
	while (t--)
	{
		string s;
		cin >> s;
		ll n = s.length();
		vi a(n + 1, 0);

		rep(i, 0, n)
		{
			if (s[i] == '<')
				a[i + 1] = max(a[i + 1], a[i] + 1);
		}
		per(i, n - 1, 0)
		{
			if (s[i] == '>')
				a[i] = max(a[i + 1] + 1, a[i]);
		}
		ll ans = 0;
		rep(i, 0, n + 1)
		ans += a[i];

		cout << ans;
	}
	return 0;
}