#include<bits/stdc++.h>
#define int long long
#define inf 0x3f3f3f3f3f3f3f 
#define GG ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define cnot cout<<"NO"<<"\n"
#define cyes cout<<"YES"<<"\n"
#define pb push_back
#define x0 first
#define y0 second
#define mem(a,b) memset(a,b,sizeof(a))
using namespace std;
typedef pair<int,string>Pis;
typedef pair<int,int>Pii;
const int N=2e5+10,mod=1e9+7,M=1e6+10;
string s1="edgnb";
void solve(){
   string s;
   cin>>s;
   int ans=0;
    for(int i=0;i<s.size();i++){
        if(s[i]=='e'){
            int f=0;
            for(int j=1;j<5;j++){
                if(i+j>=s.size())break;
                if(s[i+j]!=s1[j]){
                    f=1;
                    break;
                }

            }
            if(f==0){
                ans++;
            }
        }
    }
    cout<<ans;
}
signed main(){
    GG;
    int _t=1;
    //cin>>_t;
    while(_t--){
        solve();
    }
    
}