#include<bits/stdc++.h>
#define ll long long
#define pii pair<ll,ll>
#define lowbit(x) (x&-x)
#define log(x) (31^__builtin_clz(x))
using namespace std;

void solve(){
	string s;
	cin>>s;
	int ans=0;
	for(int i=0;i+4<s.length();i++){
		string t="";t=t+s[i]+s[i+1]+s[i+2]+s[i+3]+s[i+4];
		// cout<<t<<"\n";
		if(t=="edgnb")ans++;
	}
	cout<<ans<<"\n";
}
int main(){
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int t=1;
    // cin>>t;
    while(t--)solve();
    return 0;
}