#include<bits/stdc++.h>
using namespace std;

typedef long long int           ll;
typedef unsigned long long int  ull;
typedef vector<int>             vi;
typedef vector<ll>              vll;
typedef vector<vi>              vvi;
typedef pair<int,int>           pii;
typedef vector< pii >           vpii;
typedef set<int>                sti;

#define pb                      push_back
#define pob                     pop_back
#define mp                      make_pair
#define ff                      first
#define ss                      second
#define loop1(i,n)              for(int i=1; i<=int(n); i++)
#define loop(i,y)               for(int i=0; i<int(y); i++)
#define rloop(i,y)              for(int i=int(y); i>0; i--)
#define rloop1(i,y)             for(int i=int(y)-1; i>=0; i--)
#define read()                  freopen("input.txt", "r", stdin)
#define write()                 freopen("output.txt", "w", stdout)
#define cspf(i)                 printf("Case %d: ", i)
#define all(v)                  v.begin(),v.end()
/// Constants
#define eps                     1e-9
#define PI                      acos(-1.0)  // 3.1415926535897932

#include<stdio.h>
#include<math.h>
int main()
{
    int t;
    cin>>t;
    loop1(i,t){
        ll n,x,y,d,a,b,w,sm,sm1,ds,ydf,yde,xdf,xde;
        cin>>n>>x>>y>>d;
        if(x==y){
            cout<<"0"<<endl;
            continue;
        }
        ds=abs(x-y);
        if(ds%d==0){
            sm=ds/d;
            cout<<sm<<endl;
            continue;
        }
        ydf=abs(y-1);
        yde=abs(y-n);
        xdf=abs(x-1);
        xde=abs(x-n);
        if(xdf%d==0 && xde%d==0){
            cout<<"-1"<<endl;
            continue;
        }
        if(ydf%d==0 && yde%d==0){
            a=ceil((double)xdf/d);
            b=ydf/d;
            sm=a+b;
            a=ceil((double)xde/d);
            b=yde/d;
            sm1=a+b;
            if(sm>sm1)
                sm=sm1;
            cout<<sm<<endl;
            continue;
        }
        if(ydf%d==0){
            a=ceil((double)xdf/d);
            b=ydf/d;
            sm=a+b;
            cout<<sm<<endl;
            continue;
        }
        if(yde%d==0){
            a=ceil((double)xde/d);
            b=yde/d;
            sm=a+b;
            cout<<sm<<endl;
            continue;
        }
        cout<<"-1"<<endl;
    }
    return 0;
}