//#include <bits/stdc++.h>

#include <iostream>
#include <queue>
#include <cmath>
#include <map>
#include <cstring>
#include <algorithm>
#include <cstdio>
using namespace std;
#define Riep(n) for(int i=1;i<=n;i++)
#define Riop(n) for(int i=0;i<n;i++)
#define Rjep(n) for(int j=1;j<=n;j++)
#define Rjop(n) for(int j=0;j<n;j++)
#define mst(ss,b) memset(ss,b,sizeof(ss));
typedef unsigned long long LL;
const LL mod=1e9+7;
const double PI=acos(-1.0);
const int inf=0x3f3f3f3f;
const int N=1e6+8;
template<class T> void read(T&num) {
    char CH; bool F=false;
    for(CH=getchar();CH<‘0‘||CH>‘9‘;F= CH==‘-‘,CH=getchar());
    for(num=0;CH>=‘0‘&&CH<=‘9‘;num=num*10+CH-‘0‘,CH=getchar());
    F && (num=-num);
}
int stk[70], tp;
template<class T> inline void print(T p) {
    if(!p) { puts("0"); return; }
    while(p) stk[++ tp] = p%10, p/=10;
    while(tp) putchar(stk[tp--] + ‘0‘);
    putchar(‘\n‘);
}
int prime[N];
struct node
{
    int a[9],m;
}po[N];
void Init()
{
    for(int i=1;i<N;i++)
    {
        po[i].m=0;
    }
    for(int i=2;i<N;i++)
    {
        if(!prime[i])
        {
            po[i].a[po[i].m++]=i;
            for(int j=2*i;j<N;j+=i)
            {
                po[j].a[po[j].m++]=i;
                prime[j]=1;
            }
        }
    }
}
LL check(int x)
{
    LL s=1;
    for(int i=1;i<=x;i++)
    {
        s*=2;
    }
    return s;
}
int getans(int x,int y)
{
    int l=0,r=(int)(log(y/x+1)/log(2.0))+1;
    while(l<=r)
    {
        int mid=(l+r)>>1;
        if(check(mid)*x>=y)r=mid-1;
        else l=mid+1;
    }
    return r+1;
}
void solve(int n,LL m)
{
            if(n==1)
            {
                if(m==1)printf("0\n");
                else printf("-1\n");
            }
            else
            {
                int ans=0;
                int tempn=n;
                LL tempm=m;
                for(int i=0;i<po[n].m;i++)
                {
                    int num1=0;
                    while(tempn%po[n].a[i]==0)
                    {
                        tempn/=po[n].a[i];
                        num1++;
                    }
                    int num2=0;
                    while(tempm%po[n].a[i]==0)
                    {
                        tempm/=po[n].a[i];
                        num2++;
                    }
                    if(num2<num1)
                    {
                        printf("-1\n");
                        return ;
                    }
                    ans=max(ans,getans(num1,num2));
                }
                if(tempm>1)printf("-1\n");
                else printf("%d\n",ans);
            }
}
int main()
{
        Init();
        int T;
        scanf("%d",&T);
        int n;
        LL m;
        while(T--)
        {
            read(n);
            scanf("%I64u",&m);
            solve(n,m);
        }
    return 0;
}