#include<bits/stdc++.h>
using namespace std;
int main(){ //以 “bi” 开头的单词数量
	string s;
	int ans=0;
	getline(cin,s);
	s=" "+s;
	for(int i=0;i<s.length();i++){
		if(s[i]==' ' and s[i+1]=='b' and s[i+2]=='i')
			ans++;
	}
	cout<<ans;
	return 0;
}