#include<iostream>
#include<cstdio>
#include<cmath>
#include<string>
#include<queue>
#include<algorithm>
#include<stack>
#include<cstring>
#include<vector>
#include<list>
#include<set>
#include<map>
using namespace std;
#define ll long long
#define mod 1000000007
#define inf 999999999
//#pragma comment(linker, "/STACK:102400000,102400000")
int scan()
{
    int res = 0 , ch ;
    while( !( ( ch = getchar() ) >= ‘0‘ && ch <= ‘9‘ ) )
    {
        if( ch == EOF ) return 1 << 30 ;
    }
    res = ch - ‘0‘ ;
    while( ( ch = getchar() ) >= ‘0‘ && ch <= ‘9‘ )
        res = res * 10 + ( ch - ‘0‘ ) ;
    return res ;
}
ll a[100010];
ll b[100010];
ll gcd(ll x,ll y)
{
    if(x%y==0)
    return y;
    else
    return gcd(y,x%y);
}
void exgcd(ll a, ll b, ll &x, ll &y)
{
    if(b == 0)
    {
        x = 1;
        y = 0;
        return;
    }
    exgcd(b, a % b, x, y);
    ll tmp = x;
    x = y;
    y = tmp - (a / b) * y;
}
int main()
{
    ll x,y,z,i,t;
    ll flag=1;
    scanf("%lld",&x);
    while(x--)
    {
        scanf("%lld",&z);
        for(i=0;i<z;i++)
        scanf("%lld",&b[i]);
        for(i=0;i<z;i++)
        scanf("%lld",&a[i]);
        ll a1=a[0],b1=b[0];
        ll jie=1;
        for(i=1;i<z;i++)
        {
            ll a2=a[i],b2=b[i];
            ll xx,yy;
            ll gys=gcd(b1,b2);
            if((a2-a1)%gys)
            {
                jie=0;
                break;
            }
            exgcd(b1,b2,xx,yy);
            xx=(xx*(a2-a1))/gys;
            ll gbs=b1*b2/gys;
            a1=(((xx*b1+a1)%gbs)+gbs)%gbs;
            b1=gbs;
        }
        printf("Case %lld: ",flag++);
        if(!jie)
        printf("-1\n");
        else if(a1!=0)
        printf("%lld\n",a1);
        else
        printf("%lld\n",b1);
    }
    return 0;
}