#include<bits/stdc++.h>
using namespace std;
int main()
{
	int m,n; 
	cin>>m>>n;	
	cout<<(n-m)*30;
	
	
	
	
	
	
	
	
	
	
	
return 0;
}

/**************************************************************
	Problem: 1320
	User: 21A
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/