#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <vector>
#include <set>
#include <queue>
#include <map>
#define endl '\n'
#define int long long
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define rep2(i,a,b) for(int i=(a);i>=(b);i--)
using namespace std;
template<typename... Args>
void bubu(Args... args) { cout << ":: "; ((cout << args << " "), ...); cout << endl; }
void bubu(vector<int> tem) { for (auto x : tem) cout << x << ' '; cout << endl; }
void kuaidu() { ios::sync_with_stdio(false), cin.tie(0), cout.tie(0); }
inline int max(int a, int b) { if (a < b) return b; return a; }
inline int min(int a, int b) { if (a < b) return a; return b; }
using PII = pair<int, int>;
using i128 = __int128;

//=======================================================================
const int N = 1e5 + 10;
const int M = 1e6 + 10;
const int mod = 1e9 + 7;
const int INF = 1e16;
int n, m, T;

//=======================================================================

signed main() {
	kuaidu();
	string s; cin >> s;
	int l = s.size();
	int cnt = 0;
	rep(i, 0, l - 1) {
		if (i + 4 <= l - 1 and s[i] == 'e' and s[i + 1] == 'd' and s[i + 2] == 'g' and s[i + 3] == 'n' and s[i + 4] == 'b') cnt++;
	}
	cout << cnt << endl;
	return 0;
}