1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<cstdlib>
 5 using namespace std;
 6 
 7 int main()
 8 {
 9   int cas;
10  __int64 a,b;
11  scanf("%d",&cas);
12  for(int i=1;i<=cas;i++)
13  {
14      scanf("%I64d%I64d",&a,&b);
15      printf("Case #%d: %I64d\n",i,(b*(b+1)/2)*(b*(b+1)/2)-(a*(a-1)/2)*(a*(a-1)/2));
16  }
17  return 0;
18 }