HDU5924 Mr. Frog’s Problem

 /*
  HDU5924 Mr. Frog’s Problem
  http://acm.hdu.edu.cn/showproblem.php?pid=5924
  数论
  *
  */
 #include <cstdio>
 int main()
 {
     long long a,b;
     int t;
     scanf("%d",&t);
     for(int k=;k<=t;k++)
     {
         scanf("%lld%lld",&a,&b);
         printf("Case #%d:\n",k);
         if(a==b)
         {
             printf("1\n");
             printf("%lld %lld\n",a,b);
         }
         else
         {
             printf("2\n");
             if(a<b)
             {
                 printf("%lld %lld\n",a,b);
                 printf("%lld %lld\n",b,a);
             }
             else
             {
                 printf("%lld %lld\n%lld %lld\n",b,a,a,b);
             }
         }

     }
     return ;
 }