#include <iostream>
using namespace std;
int main(){
	int a,b;
	cin>>a>>b;
	if((a<=25 and b>=25) or (a>25 and b<=31)) cout<<"0"<<endl;
	else if(a<=24 and b>=24) cout<<"1"<<endl;
	else if(a<=23 and b>=23) cout<<"2"<<endl;
	else cout<<"3"<<endl;
	return 0;
}