#pragma GCC optimize(1)
#pragma GCC optimize(2)
#pragma GCC optimize(3, "Ofast", "inline")

#include <bits/stdc++.h>

#define int long long
#define ld long double
#define i32 int
#define u32 unsigned int
#define i64 long long
#define u64 unsigned long long
#define u27 __int128
#define endl '\n'
#define VI vector<int>
#define VVI vector<VI>
#define rand() RANDOM(GEN)
#define IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define CTM (cout<<"Time:"<<static_cast<double>(clock()-START_TIME)/CLOCKS_PER_SEC*1000<<"ms"<<endl)
typedef long long ll;

using namespace std;
random_device SEED;
mt19937_64 GEN(SEED());
uniform_int_distribution<u64> RANDOM(0, numeric_limits<u64>::max());
const clock_t START_TIME = clock();

signed main() {
#ifndef ONLINE_JUDGE
    freopen(".in", "r", stdin);
    freopen(".out", "w", stdout);
#endif
    IO;
    string res;
    int pos=0,ans=0;
    cin>>res;
    auto r=res.find("edgnb",0);
    while(r!=string::npos) {
        ans++,
        pos=r+5;
        r=res.find("edgnb",pos);
    }
    cout<<ans;
    return 0;
}