#include<iostream>
#include<string>
using namespace std;
int main(){
    string s;cin>>s;int f = 0;
    for(int i = 0;i<=s.length()-4;i++){
        string v = "";
        for(int j = i;j<=i+4;j++){
            v+=s[j];
        }
        if(v == "luogu") f++;
    }
    cout<<f<<endl;
    return 0;
}