1 //2016.8.17
 2 #include<iostream>
 3 #include<cstdio>
 4 #define ll unsigned long long
 5 using namespace std;
 6 
 7 ll gcd(ll a, ll b)
 8 {
 9     return b==0?a:gcd(b, a%b);
10 }
11 
12 int main()
13 {
14     int T, cnt;
15     bool fg;
16     ll n, m;
17     cin>>T;
18     while(T--)
19     {
20         scanf("%I64d%I64d", &n, &m);
21         if(n==m){
22             puts("0");
23             continue;
24         }
25         if(n==0||m<n||m%n!=0)
26         {
27             puts("-1");
28             continue;
29         }
30         fg = true; cnt = 0;
31         while(m != n)
32         {
33             ll tmp = gcd(n, m/n);
34             if(tmp == 1){
35                 fg = false;
36                 break;
37             }
38             n *= tmp;
39             cnt++;
40         }
41         if(fg)
42             printf("%d\n", cnt);
43         else 
44               printf("-1\n");
45     }
46 
47     return 0;
48 }