#include<bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define F first
#define S second
signed main(){
	ios_base::sync_with_stdio(NULL);
	cin.tie(NULL);
	cout.tie(NULL);
	string s, str = "";
	cin >> s;
	int cnt = 0;
	int n = s.size();
	for(int i = 0; i < n-4; i ++ ){
		if( s[i] = 'e' && s[i+1] == 'd' && s[i+2] == 'g' && s[i+3] == 'n' && s[i+4] == 'b' ){
			cnt ++;
		}
	}
	cout << cnt << "\n";
}