#include <bits/stdc++.h>
#include <iostream>

using namespace std;
 
typedef long long ll;

typedef long double ld;
typedef unsigned long long ull;
typedef pair<int,int> PII;
typedef pair<ll,ll> PLL;
#define i128 _int128

#define fi first
#define se second 
#define pb push_back

#define ICPC_CD return
#define Chong 0
#define endl '\n'

const ll INF=0x3f3f3f3f;
const ll N=1e6+9;
const ll mod=998244353;

string s="edgnb",str;
int ans;

void solve(){
    cin>>str;ans=0;
    for(int i=0;i<=str.size()-5;i++){
        if(str.substr(i,5)==s){
            //cout<<str.substr(i,5)<<endl;
            ans++;
            i+=4;
        }
    }
    
    cout<<ans<<endl;
    
    
}

signed main(){
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    
    int _=1;
    //cin>>_;
    
    while(_--)solve();

    ICPC_CD Chong;
}