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

/**************************************************************
	Problem: 1320
	User: sucongyi
	Language: C++
	Result: Accepted
	Time:16 ms
	Memory:2072 kb
****************************************************************/