#include<bits/stdc++.h>
using namespace std;
int main(){
    int a,b;
    cin>>a>>b;
    cout<<(b-a)*30;
    return 0;
} 
/**************************************************************
	Problem: 1320
	User: binzicheng1
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2072 kb
****************************************************************/