#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const LL N = 5010;
inline LL read()
{
  LL p=0; LL f=1; char ch=getchar();
  while(ch<'0' || ch>'9'){if(ch=='-') f=-1; ch=getchar();}
  while(ch>='0' && ch<='9'){p=p*10+ch-'0'; ch=getchar();}
  return p*f;
}
LL n,d,a[N],h[N];
int main()
{
  LL t = read();
  for(LL Tcase=1;Tcase<=t;Tcase++)
  {
    printf("Case #%lld: ",Tcase);
    n = read(); d = read(); d<<=1; bool bk = 1;
    LL sum = 0; for(LL i=1;i<=n;i++) a[i] = read();
    for(LL i=1;i<=n;i++) for(LL j=i;j<=n;j+=d) if(a[i] != a[j]){bk = 0;}
    n = d; h[1] = a[1] - a[n]; for(LL i=2;i<=n;i++) h[i] = a[i] - a[i-1];
    sum = 0; for(int i=1;i<=n;i++) sum += a[i];
    if(!bk){printf("CHEATERS!\n"); continue;}
    LL ans = 0;
    for(LL i=d/2;i>=1;i>>=1)
    {
      for(LL j=1;j<=i;j++)
      {
        LL s = abs(h[j] - h[j+i]);
        if(s&1){bk = 0; break;}
        else
        {
          if(h[j] < h[j+i]) h[j] += s/2,h[j+i] -= s/2;
          else h[j] -= s/2,h[j+i] += s/2;
          ans+=s/2; sum -= s/2 * n/2;
        }
      }
      if(!bk) break;
    }
    if(!bk || sum < 0){printf("CHEATERS!\n"); continue;}
    else printf("%lld\n",ans);
  }
  return 0;
}