#include <bits/stdc++.h>
using namespace std;
 
struct Point {
    double x, y;
};
 
int t;
Point A, B;
 
double dist(Point A, Point B) {
    return sqrt((A.x - B.x) * (A.x - B.x) + (A.y - B.y) * (A.y - B.y));
}
 
int main() {
    cin >> t;
    while (t--) {
        cin >> A.x >> A.y >> B.x >> B.y;
        A.y = abs(A.y);
        B.y = abs(B.y);
 
        Point antiB;
        antiB.x = B.x;
        antiB.y = -B.y;
 
        int res = dist(A, antiB);
        cout << res << "\n";
    }
    return 0;
}
 

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