RQNOJ 358线段

#include <cmath>

#include <cstdio>

#include <iostream>



using namespace std;



double dis(double x1, double y1, double x2, double y2) {

	return sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));

}



int main() {

	double x1, y1, r1, x2, y2, r2;

	while (scanf("%lf%lf%lf%lf%lf%lf", &x1, &y1, &r1, &x2, &y2, &r2) != EOF) {

		double d = dis(x1, y1, x2, y2);

		printf ("%.6lf\n", 2*d); 

	}

	return 0;

}