#include <iostream>
#include <cmath>
using namespace std;


void solve(){
        long long a, b, c, d;
        cin >> a >> b >> c >> d;

       if(d<b){
               cout<<"-1\n";
               return;
       }
       long long res,aa;
       aa=a+d-b;
       if(aa<c){
               cout<<"-1\n";
               return;
       }
       res=(d-b)+abs(aa-c);
       cout<<res<<"\n";


}

int main() {
    int t;
    cin >> t;

    while (t--) {
            solve();
    }

    return 0;
}