The first line contains one integer tt (1≤t≤1031≤t≤103) — the number of testcases.

Each testcase is denoted by a line containing four integers nn, xx, yy, dd (1≤n,d≤1091≤n,d≤109, 1≤x,y≤n1≤x,y≤n) — the number of pages, the starting page, the desired page, and the number of pages scrolled by pressing one button, respectively.

Print one line for each test.

If Vasya can move from page xx to page yy, print the minimum number of times he needs to press a button to do it. Otherwise print −1−1.

3
10 4 5 2
5 1 3 4
20 4 19 3

4
-1
5

In the first test case the optimal sequence is: 4→2→1→3→54→2→1→3→5.

In the second test case it is possible to get to pages 11 and 55.

In the third test case the optimal sequence is: 4→7→10→13→16→194→7→10→13→16→19.

翻到頭只能從頭翻，翻到尾只能從尾倒著翻。

程式碼:

 1 //A
 2 #include<bits/stdc++.h>
 3 using namespace std;
 4 typedef long long ll;
 5 const int maxn=1e5+10;
 6 const int inf=0x3f3f3f3f;
 7 
 8 int main()
 9 {
10     int t;
11     cin>>t;
12     while(t--){
13         int n,x,y,d,ans=inf;
14         cin>>n>>x>>y>>d;
15         if(abs(y-x)%d==0) {ans=min(ans,abs(y-x)/d);}
16         if((y-1)%d==0) {ans=min(ans,x/d+(y-1)/d+(x%d==0?0:1));}
17         if((n-y)%d==0) {ans=min(ans,(n-x)/d+(n-y)/d+((n-x)%d==0?0:1));}
18         if(ans==inf) cout<<-1<<endl;
19         else cout<<ans<<endl;
20     }
21 }