1 //2016.9.13
 2 #include <iostream>
 3 #include <cstdio>
 4 #define N 105
 5 
 6 using namespace std;
 7 
 8 int main()
 9 {
10     int T, kase = 0, ans, n, a, b, len, l[N], r[N];
11     scanf("%d", &T);
12     while(T--)
13     {
14         int tmp = 0;
15         ans = 0;//假设最初需要0点能量
16         scanf("%d%d%d%d", &n, &a, &b, &len);
17         l[0] = r[0] = 0;
18         for(int i = 1; i <= n; i++)
19         {
20             scanf("%d%d", &l[i], &r[i]);
21             tmp = tmp+b*(l[i]-r[i-1])-a*(r[i]-l[i]);
22             if(ans > tmp)ans = tmp;
23         }
24         printf("Case #%d: %d\n", ++kase, -ans);
25     }
26 
27     return 0;
28 }