#include<bits/stdc++.h>
#define fi first
#define se second
#define MULT_TEST 0
using namespace std;
typedef unsigned long long ull;
const int INF = 0x3f3f3f3f;
const int MOD = 998244353;
const int N = 200005;
char s[N];
inline int read() {
    int w = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9') {
        if (ch == '-') f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9') {
        w = (w << 1) + (w << 3) + ch - 48;
        ch = getchar();
    }
    return w * f;
}
inline void Solve() {
    int ans = 0;
    scanf("%s", s + 1);
    int n = strlen(s + 1);
    if (n < 5) return printf("0\n"), void();
    for (int i = 5; i <= n; i++) 
        if (s[i - 4] == 'e' && s[i - 3] == 'd' && s[i - 2] == 'g' && s[i - 1] == 'n' && s[i] == 'b') ans++;
    printf("%d\n", ans);
}
signed main() {
    int T = 1;
#if MULT_TEST
    T = read();
#endif 
    while (T--) Solve();
    return 0;
}