#include<bits/stdc++.h>
using namespace std;
int main() 
{
    int N;
    string S;
    cin>>N>>S;
    int ans=0,cnt=0;
    for (int i=0;i<N-1;i++) 
	{
        if (S[i]=='>')
            cnt++;
        else
            cnt=0;
        ans+=cnt;
    }
    cout<<ans<<"\n";
    return 0;
}