0tps

#include<bits/stdc++.h>
using namespace std;
int main(){
	string s;
	cin>>s;
	int sum=0,l=s.size();
	for(int i=0;i<l-2;){
		if((s[i]=='l'||s[i]=='q'||s[i]=='b')&&(s[i+1]=='l'||s[i+1]=='q'||s[i+1]=='b')&&(s[i+2]=='l'||s[i+2]=='q'||s[i+2]=='b')&&(s[i]!=s[i]&&s[i]!=s[i+2]&&s[i+1]!=s[i+2])){
			sum++,i+=3;			
		}
		else{
			i++;			
		}
	}
	cout<<sum<<endl;
	return 0;
}