#include<iostream>
#include<string.h>
#include<algorithm>
#include<math.h>
#include<vector>
#include<map>
#include<queue>
#include<set> 
#include<stack>
#include<bitset>
#include<unordered_map>
#include<iomanip>
#include<cassert>
#include<array>
#define fi first
#define se second
#define endl '\n'
#define pb push_back
#define ep emplace_back 
#define debug(x) cout<<x<<'\n'
#define RES cout<<res<<'\n'
#define ANS cout<<ans<<'\n'
#define YES	cout<<"YES"<<'\n'
#define NO cout<<"NO"<<'\n'
#define Yes	cout<<"Yes"<<'\n'
#define No cout<<"No"<<'\n'
#define me(a,x) memset(a,x,sizeof(a))
#define L(i,j,k) for(int i=(j);i<=(k);++i)
#define R(i,j,k) for(int i=(j);i>=(k);--i)
#define r23 cout<<233<<endl;return;
#define int long long 
using namespace std;
typedef long long ll;
typedef pair<int,int> PII;
typedef pair<PII,int> PIII;
typedef unsigned long long ull;
const int N=1e5+5,P=131,mod=998244353;
int qmi(int a,int b){
	int res=1;
	while(b){
		if(b&1)res=res*a%mod;
		a=a*a%mod;
		b>>=1;
	}
	return res;
}
int inv(int a,int b){
	return qmi(a,b-2);
}
void solve(){
	string s;cin>>s;
	int res=0;
	for(int i=0;s[i];i++){
		if(s.substr(i,5)=="edgnb")res++;
	}
	RES; 
}
signed main(){
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	int T=1;
	//cin>>T;
	while(T--){
		solve();
	}
}