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#include<stdio.h>
int f(int x,int n,int mod) {
	int res=1;
	while(n>0) {
		if(n&1)
			res=(res*x)%mod;
		x=(x*x)%mod;
		n>>=1;
	}
	return res;
}
int main() {
	int T,kase=0;
	scanf("%d",&T);
	while(T--) {
		int n,K,MOD;;
		scanf("%d %d %d",&n,&K,&MOD);
		int sum=0;
		for(int i=0; i<n; i++) {
			int t;
			scanf("%d",&t);
			sum=sum+t%MOD;
		}
		sum%=MOD;
		int k=K%MOD;
		int res=f(n,K-1,MOD);
		printf("Case %d: ",++kase);
		printf("%d\n",(long long)((long long)sum*(long long)k*(long long)res)%MOD);
	}
	return 0;
}