#include<stdio.h>
void main()
{
	int t,m,n;
	scanf("%d%d",&m,&n);
	t=(n-m)*30;
	printf("%d\n",t);

  }  
/**************************************************************
	Problem: 1320
	User: admin
	Language: C
	Result: Accepted
	Time:8 ms
	Memory:1144 kb
****************************************************************/