#include<bits/stdc++.h>
using namespace std;
inline void readSL(std::string &s){
	char ch=getchar();
	while(ch=='\n') {
	ch=getchar();
	}
	while(ch!='\n') s+=ch,ch=getchar();
}

inline void write(int x)
{
    if(x<0){
    	putchar('-');
		x=-x;
	}
    if(x>9) 
		write(x/10);
    putchar(x%10+'0');
}

 
int main(){
	 
string s;
     readSL(s);
    string a="edgnb";
    //cout<<s.length()<<endl;
	int ans=0;
	for(int i=0;i<s.length()-4;i++){
		
		for(int j=0;j<=4&&j+i<s.length();j++){
			if(j==4&&a[j]==s[i+j]){
				i=i+4;
				ans++;
				break;
			}
			if(s[i+j]!=a[j]){
				i=i+max(0,j-1);
				break;
			}
		}
	}
	write(ans);
}