/* Problem 1--Making Waves
   This was handled rather easily by simple trial and error! */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define Pi 3.1415926535897932384626433832795

int main (int argc, char **argv);

int main (int argc, char **argv) {

  int cs, N, i, f1, f2, found;
  FILE *in, *out;
  double f[1000];

 in = fopen ("prob1.in","r");
 out = fopen ("prob1.out","w");
 for (cs=1;fscanf (in,"%d",&N),N!=0;cs++) {
  for (i=0;i<N;i++) fscanf (in,"%lf",&f[i]);
  found = 0; /* Go through all frequency possibilities */
  for (f1=400;f1 < 600 && !found;) {
   f2 = f1+1;
   for (f2=f1+1;f2<=600 && !found;) {
    found = 1;
    for (i=1;i<=N && found;i++)
     found = fabs (sin(Pi/180*i/N*f1)+sin(Pi/180*i/N*f2)-f[i-1])<1e-5;
    if (!found) f2++;
   }
   if (!found) f1++;
  }
  fprintf (out,"Case %d, f1 = %d, f2 = %d\n",cs,f1,f2);
 }
 fclose (in);
 fclose (out);
 return EXIT_SUCCESS;
}