#include<iostream>
#include<string>
#define int long long
using namespace std;
const int N=1e6+5;
string a,b="friend";
int len,ans;
signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	//freopen("qq.out","r",stdin);
	cin>>a;
	len=a.size();
	for(int i=0,j=0;i<len;i++){
		if(a[i]==b[j])j++;
		else j=0;
		if(j==6){
		    ans++,j=0;
		    for(int k=i;k<i+4;k++)if(k<len)a[k]='*';
		}
	}
	cout<<ans;
	//cout<<"\n"<<a;
	return 0;
}
//friendfffrined