1213

    #include<iostream>
    #include<bits/stdc++.h>

    using namespace std;

    #define lld long long int

    lld solve(lld n, lld k, lld MOD)
    {
        if(k==0)
            return 1;
        if(k%2==1)
            return ((n%MOD)*solve(n,k-1,MOD)%MOD)%MOD;
        lld res = solve(n,k/2,MOD)%MOD;
        return (res*res)%MOD;
    }


    int main()
    {
        int test;
        lld n,k,MOD,res,num;

        cin>>test;

        for(int Case = 1; Case<=test; Case++)
        {
            res = 0;

            scanf("%lld %lld %lld",&n,&k,&MOD);
            for(int i=0;i<n;i++)
            {
                scanf("%lld",&num);
                res+=num%MOD;
            }
            res = res%MOD;

            res = (res*k)%MOD;

            res = (res*solve(n,k-1,MOD))%MOD;

            printf("Case %d: %lld\n",Case,res);


        }

        return 0;
    }