#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <iostream>
#include <cmath>
#include <map>
#include <bitset>
#include <stack>
#include <queue>
#include <vector>
#include <bitset>
#include <set>
#define MM(a,b) memset(a,b,sizeof(a));
#define inf 0x3f3f3f3f
using namespace std;
typedef long long ll;
#define CT continue
#define SC scanf
const int N=2*1e5+10;
int factor[N],num[N],appear[N],step[N];
ll add[N];

int gcd(int a,int b)
{
   if(b==0) return a;
   else return gcd(b,a%b);
}

int main()
{
    int cas,n,m,kk=0;
    SC("%d",&cas);
    while(cas--){
        SC("%d%d",&n,&m);
        int cnt=0;MM(num,0);MM(appear,0);
        for(int i=1;i<=n;i++) SC("%d",&step[i]);
        for(int i=1;i*i<=m;i++)  if(m%i==0){
           factor[++cnt]=i;
           if(i*i!=m) factor[++cnt]=m/i;
        }
        sort(factor+1,factor+cnt+1);
        cnt--;
        for(int i=1;i<=cnt;i++){
            ll k=(m-1)/factor[i];
            add[i]=k*(k+1)/2*factor[i];
        }

        for(int i=1;i<=n;i++){
            int k=gcd(step[i],m);
            for(int j=1;j<=cnt;j++)
                if(factor[j]%k==0) appear[j]=1;
        }

        ll ans=0;
        for(int i=1;i<=cnt;i++) if(num[i]!=appear[i]){
            ans+=add[i]*(appear[i]-num[i]);
            for(int j=i+1;j<=cnt;j++)
                if(factor[j]%factor[i]==0) num[j]+=(appear[i]-num[i]);
        }
        printf("Case #%d: %lld\n",++kk,ans);
    }
    return 0;
}