#include<stdio.h>
//#include<bits/stdc++.h>
#include<string.h>
#include<iostream>
#include<math.h>
#include<sstream>
#include<set>
#include<queue>
#include<map>
#include<vector>
#include<algorithm>
#include<limits.h>
#define inf 0x3fffffff
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define LL long long
using namespace std;
int a;
int main()
{
    int t;
    int x,y,l,h;
    while(cin>>t)
    {
        while(t--)
        {
            cin>>x>>y>>l>>h;
            if(l%x==0)
            {
                h=h-(l/x-1)*y;
                if(h>=0)
                {
                    cout<<l/x<<endl;
                }
                else
                {
                    puts("-1");
                }
            }
            else
            {
                h=h-(l/x)*y;
                if(h>=0)
                {
                    cout<<l/x+1<<endl;
                }
                else
                {
                    puts("-1");
                }
            }
        }
    }
    return 0;
}