/*by SilverN*/

 #include<iostream>

 #include<algorithm>

 #include<cstring>

 #include<cstdio>

 #include<cmath>

 #define LL long long

 using namespace std;

 int read(){

     int x=,f=;char ch=getchar();

     while(ch<'' || ch>''){if(ch=='-')f=-;ch=getchar();}

     while(ch>='' && ch<=''){x=x*+ch-'';ch=getchar();}

     return x*f;

 }

 LL f[][][][];//[位数][R比O多的个数][首O][尾O]

 const int bas=;

 int n;

 int main(){

     int i,j,cas=;

     while(scanf("%d",&n) && n){

         printf("Case %d: ",++cas);

         if(n& || n<){printf("0\n");continue;}

         memset(f,,sizeof f);

         f[][+bas][][]=f[][bas-][][]=;

         for(i=;i<=n;i++){

             for(j=-;j<=;j++){

                 f[i][j+bas][][]=f[i-][j-+bas][][]+f[i-][j-+bas][][];

                 f[i][j+bas][][]=f[i-][j++bas][][];

                 f[i][j+bas][][]=f[i-][j-+bas][][]+f[i-][j-+bas][][];

                 f[i][j+bas][][]=f[i-][j++bas][][];

             }

         }

         LL ans=f[n][+bas][][]+f[n][+bas][][]+f[n][+bas][][];

         printf("%lld\n",ans);

     }

     return ;

 }