hdu 2134 Cuts the cake

#include<stdio.h>
#include<math.h>
int main()
{
    int r;
    while(scanf("%d",&r)!=EOF&&r!=0)
    {
        double s=(double)r*r;
        //double s=r*r;//会wrong
        double r1=sqrt(s/3);
        double r2=sqrt(s*2/3);
        printf("%.3lf %.3lf
",r1,r2);
    }
    return 0;
}