#include <cstring>
#include <iostream>
#include <algorithm>
#include <queue>
#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> PII;
#define int long long
typedef long long ll; 

const int N = 1e5+10;
const int mod = 998244353;


void solve()
{
    string s;
    cin>>s;
    string ss = "edgnb";
    int ans = 0;
    for(int i = 0;i<s.size();i++)
    {
        if(s[i]=='e')
        {
            int j = i;
            int cnt = 0;
            while(j<s.size()&&cnt<5&&ss[cnt]==s[j])
            {
                cnt++;
                j++;
            }
            if(cnt>4)
            {
                ans++;
                i = j-1;
            }
        }
    }

    cout<<ans<<endl;





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