#include<stdio.h>
#include<math.h>
int main() {
    int n;
    double x1,y1,x2,y2;
    if(scanf("%d",&n)!=1){printf("Invalid input");
    return 0;}
    while(n--)
    {if(scanf("%1f%1f%1f%1f",&x1,&y1,&x2,&y2)!=4){printf("Invalid input"),return 0;}
    printf("%.2f\n",sqrt(x2-x1)*(x2-x1)+(y2-11)*(y2-y1));}
    return 0;
    }