#include<iostream.h>
#include<math.h>
void main()
{
    double a,b,c,x1,x2,m;
    cout<<"please input  three  nummber  for  a   b   c  :"<<endl;
    cin>>a>>b>>c;
 
    m=(b*b-4*a*c);
    if(m<0)
        cout<<"the  fang cheng  isn't   answer:"<<endl;


    else
    {

    x1=(-b+sqrt(m))/(2*a);
    x2=(-b-sqrt(m))/(2*a);
    cout<<"x1="<<x1<<"x2="<<x2<<endl;
    }



    }