#include<bits/stdc++.h>
using namespace std;
#define fast ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define int long long
const int N=2e6+7;
int n,m;
void solve(){
	string s;
	cin>>s;
	int len=s.length();
	string ss="edgnb";
	int ans=0;
	int i=0,j=0;
	for(;i<len;i++){
		j=0;
		for(;j<5;j++){
			if(ss[j]!=s[i+j]) break;
		}
		if(j==5) ans++;
	}
	cout<<ans<<endl;
}
signed main(){
	fast;
	int t=1;
	//cin>>t;
	while(t--){
		solve();
	}
}