C :

#include<stdio.h>
int main()
{
	int n,d,count=0;
	while(scanf("%d%d",&n,&d)!=EOF,n||d)
	{
		int p,l,v;
		float sum=0,t=0;
		while(n--)
		{
			scanf("%d%d%d",&p,&l,&v);
			t+=l*2.0/v;
			sum+=l;		
		}
		t=t+d-sum;
		count++;
		printf("Case %d: %.3f\n\n",count,t);
	}
	return 0;
}

C++ :

#include <stdio.h>

int main() {
	int n, c = 0;
	double d, p, l, v, ans;
	while (scanf("%d%lf", &n, &d) != EOF, n || d) {
		ans = 0;
		while (n--) {
			scanf("%lf%lf%lf", &p, &l, &v);
			ans += 2.0 * l / v;
			d -= l;
		}
		printf("Case %d: %.3lf\n\n", ++c, d + ans);
	}
	return 0;
}