#include<bits/stdc++.h>
using namespace std;
bool flag=1;
int main()
{
	int t;
	cin>>t;
	while(t--)
	{
		flag=1;
		long long n,k,t=1;
		cin>>n>>k;
		long long m=(n-k)/t;
		if(n<=k) cout<<"-1"<<endl;
		else
		{
			while(m>(n/2))
			{
				if((n-m)%m!=k) t++;
			    else 
				{
					flag=0;
					cout<<n-m<<" "<<m<<endl;
					break;
				}
				m=(n-k)/t;
			}
		}
		if(flag) cout<<"-1"<<endl;
		 //cout<<k<<" "<<n-k<<endl;
		/*x+y=n;x=my+k;
		y=(n-k)/(m+1)
		(x,y)=1;
		*/
	}
	return 0;
}