1 //
 2 //by coolxxx
 3 //#include<bits/stdc++.h>
 4 #include<iostream>
 5 #include<algorithm>
 6 #include<string>
 7 #include<iomanip>
 8 #include<map>
 9 #include<stack>
10 #include<queue>
11 #include<set>
12 #include<bitset>
13 #include<memory.h>
14 #include<time.h>
15 #include<stdio.h>
16 #include<stdlib.h>
17 #include<string.h>
18 //#include<stdbool.h>
19 #include<math.h>
20 #pragma comment(linker,"/STACK:1024000000,1024000000")
21 #define min(a,b) ((a)<(b)?(a):(b))
22 #define max(a,b) ((a)>(b)?(a):(b))
23 #define abs(a) ((a)>0?(a):(-(a)))
24 #define lowbit(a) (a&(-a))
25 #define sqr(a) ((a)*(a))
26 #define swap(a,b) ((a)^=(b),(b)^=(a),(a)^=(b))
27 #define mem(a,b) memset(a,b,sizeof(a))
28 #define eps (1e-10)
29 #define J 10000
30 #define mod 1000000007
31 #define MAX 0x7f7f7f7f
32 #define PI 3.14159265358979323
33 #define N 100004
34 using namespace std;
35 typedef long long LL;
36 double anss;
37 LL aans;
38 int cas,cass;
39 LL n,m,lll,ans;
40 
41 int main()
42 {
43     #ifndef ONLINE_JUDGEW
44 //    freopen("1.txt","r",stdin);
45 //    freopen("2.txt","w",stdout);
46     #endif
47     int i,j,k;
48     int x,y,z;
49 //    init();
50 //    for(scanf("%d",&cass);cass;cass--)
51     for(scanf("%d",&cas),cass=1;cass<=cas;cass++)
52 //    while(~scanf("%s",s))
53 //    while(~scanf("%d%d",&n,&m))
54     {
55         printf("Case #%d: ",cass);
56         scanf("%lld",&n);
57         if(n==2)puts("2");
58         else printf("%lld\n",n*(n+1)/2-1);
59     }
60     return 0;
61 }
62 /*
63 //
64 
65 //
66 */