#include <bits/stdc++.h>
using namespace std;
#define LL long long
const double PI = acos(-1.0);

void sol() {
    string s;
    cin >> s;
    int n = s.size(), ans = 0;
    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')
            ans += 1;
    }
    cout << ans << '\n';
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int _ = 1;
    // cin >> _;
    while (_--) sol();
    return 0;
}