int main(){
	unsigned long long int x,n;
  unsigned long long int sum;
	scanf("%lld %lld",&x,&n);
	sum=0;
	if(x==6||x==7)
		sum=(n-(8-x))/7*1250+(n-(8-x))%7*250;
	else
		sum=(6-x)*250+(n-(8-x))/7*1250+(n-(8-x))%7*250;
	printf("%lld",sum);
		
		
	return 0;
}