CAU TRUC DIEM

#include<iostream>
#include<cmath>
#include<iomanip>
using namespace std;
struct Point{
     double x, y;

};
void input(struct Point &A){
    cin >> A.x >> A.y;
}
double distance(struct Point &A, struct Point &B){
    double res = sqrt(pow(B.x-A.x,2)+pow(B.y-A.y,2));
    return res;
}
int main(){
    struct Point A, B;
    int t;
    cin>>t;
    while(t--){
        input(A); input(B);
        cout << fixed << setprecision(4) << distance(A,B) << endl;
    }
    return 0;
}