水题
#include<stdio.h>
#include<iostream>
#include<math.h>
#include<string.h>
#include<iomanip>
#include<stdlib.h>
#include<ctype.h>
#include<algorithm>
#include<deque>
#include<functional>
#include<iterator>
#include<vector>
#include<list>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<sstream>
#define CPY(A,B)memcpy(A,B,sizeof(A))
typedef long long LL;
typedef unsigned long long uLL;
const int MOD=1e9+7;
const int INF=0x3f3f3f3f;
const LL INFF=0x3f3f3f3f3f3f3f3fLL;
const double EPS=1e-9;
const double OO=1e20;
const double PI=acos (-1.0);
int dx[]= {0,1,0,-1};
int dy[]= {1,0,-1,0};
int gcd (const LL &a,const LL &b) {return b==0?a:gcd (b,a%b);}
using namespace std;
int main() {
int n,G,L;
while (scanf ("%d",&n) !=EOF)
for (int t=1; t<=n; ++t) {
scanf ("%d%d",&G,&L);
if (L%G==0) {
printf ("%d %d\n",G,L);
} else {printf ("-1\n");}
}
return 0;
}