#include <bits/stdc++.h>
using namespace std;
double a,b;
int main()
{
cin>>a>>b;
if (a!=0) cout<<"Phuong trinh co nghiem duy nhat la:"<<fixed<<setprecision(2)<<-b/(2*a);
else if ((b==0) and (a==0)) cout<<"Phuong trinh co vo so nghiem";
else if ((a==0) and (b!=0)) cout<<"Phuong trinh vo nghiem";
return 0;
}