include[HTML_REMOVED]
include[HTML_REMOVED]
include[HTML_REMOVED]
using namespace std;
int main(){
double x1,y1;
double x2,y2;
scanf(“%lf %lf”,&x1,&y1);
scanf(“%lf %lf”,&x2,&y2);
double distance;
distance=sqrt((x2-x1)(x2-x1)+(y2-y1)(y2-y1));
printf(“%.4lf”,distance);
return 0;
}