#include<stdio.h>
int main()
{
	long long int time,xingqi,zhou,s=0,shengyu;
	scanf("%lld%lld",&xingqi,&time);
	zhou=time/7;
	s=250*5*zhou;
	shengyu=time-7*zhou;
	for(;xingqi<xingqi+shengyu;xingqi++)
			switch(xingqi)
		{
			case 1:
			case 2:
			case 3:
			case 4:
			case 5:s=s+250;break;
			case 6:s=s;break;
			case 7:s=s;break;
		}
		printf("%lld",s);
		return 0;
}