#include <iostream>
#include <math.h>
using namespace std;

int ptBac2(float a, float b, float c, float &x1, float &x2){
	float delta = b*b- 4*a*c;
	if(delta<0){
	return 0;
	}
	else if(delta==0){
		x1=x2=-b/(2*a);
		return 1;
	}
	else{
		delta =sqrt(delta);
		x1 = (-b + delta)/(2*a);
		x2 =(-b -delta)/(2*a);
		return 2;
		}

}
int main(){
	float a,b,c;
	float x1,x2;
	do{
		cout<<"nhap a!=0 "<<endl;
		cin>>a;
		cout<<"Nhap b: "<<endl;
		cin>>b;
		cout<<"nhap c: "<<endl;
		cin>>c;
	}while(!a);
	int so=ptBac2(a,b,c,x1,x2);
	if(so==0){
		cout<<"pt vo ngiem";
	}
	else if(so==1){
		cout<<"pt co nghiem kep"<<x1;
		
	}
	else{
		
		cout<<"pt co 2 ngiem phan biet"<<endl;
		cout<<"x1"<<x1<<endl;
		cout<<"x2"<<x2<<endl;
		}
		
}