#include <bits/stdc++.h>
using namespace std;
int main(){
	int m,n,a;
	cin>>m>>n;
	a=(n-m)*30;
	cout<<a;
}
/**************************************************************
	Problem: 1320
	User: tonghuatao
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2072 kb
****************************************************************/