#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 100100 , M = 12;
int n , X , Y , a[N];
int cX[M] , cY[M];
int cntMX[N][M] , cntMN[N][M];

void solve(){

scanf("%d %d %d",&n,&X,&Y);
for(int i=0;i<n;i++)scanf("%d",a+i);

// check if impossible
if( Y%X || (n == 1 && X!=Y) ){
    printf("-1\n");
    return;
}

int ans=0;
for(int i=0;i<n;i++)
    if( a[i]%X || Y%a[i] )
        ans++;

if( ans > 1 ){
    printf("%d\n",ans);
    return;
}

ll gcd=a[0],lcm=a[0];
for(int i=1;i<n;i++)
    gcd=__gcd(gcd,1ll*a[i]),
    lcm=lcm / __gcd(lcm,1ll*a[i]) *a[i];

if( gcd == X && lcm == Y ){
    printf("0\n");
    return;
}

int tmp=Y;
vector<int>primes;
for(int i=2;i*i<=tmp;i++)
    if( tmp%i==0 ){
        primes.push_back(i);
        while( tmp%i==0 )tmp/=i;
    }
if( tmp!=1 )primes.push_back(tmp);


int m = primes.size();
for(int j=0;j<m;j++){

    cX[j]=cY[j]=0;
    while( X%primes[j]==0 )X/=primes[j],cX[j]++;
    while( Y%primes[j]==0 )Y/=primes[j],cY[j]++;

    for(int i=0;i<n;i++){

        cntMX[i][j]=cntMN[i][j]=0;
        int c=0;
        while( a[i]%primes[j]==0 )a[i]/=primes[j],c++;
        cntMX[i][j]=( c == cY[j] );
        cntMN[i][j]=( c == cX[j] );

        if( i )
            cntMX[i][j]+=cntMX[i-1][j],
            cntMN[i][j]+=cntMN[i-1][j];
    }
}


for(int i=0;i<n;i++){ // change only element A[i]

      bool ok=1;
      for(int j=0;j<m;j++){

        int preMN = (( i>0 )?cntMN[i-1][j]:0);
        int preMX = (( i>0 )?cntMX[i-1][j]:0);

        int sufMN = cntMN[n-1][j]-cntMN[i][j];
        int sufMX = cntMX[n-1][j]-cntMX[i][j];

        if( cX[j]!=cY[j] )
        if( preMN+preMX+sufMN+sufMX ==0 ){
            ok=0;
            break;
        }
      }
      if(!ok)continue;
      printf("1\n");
      return;
}
printf("2\n");
return;
}

int main(){

int t;
scanf("%d",&t);
while( t-- )solve();

return 0;
}