#include<bits/stdc++.h>
using namespace std;
 int main(){
 	int m,n,d,e;
 	cin>>m>>n;
 	e=30;
 	d=(n-m)*e;
 	cout<<" "<<d;
 } 
/**************************************************************
	Problem: 1320
	User: binzicheng
	Language: C++
	Result: Presentation Error
****************************************************************/