Constructor Overloading

#include<iostream>
    using namespace std;

    class Car{
    int number;
    public:

    Car(){
    cout<<"\nConstructor Car()"<<endl;
    }

    Car(int n){
    cout<<"\nConstructor Car(int n)"<<endl;
    number=n;
    }

    Car(int a,int b){
    cout<<"\nConstructor Car(int a,int b)"<<endl;
    cout<<"Sum="<<(a+b);
    }

    void displayValue(){
    cout<<"Number="<<number;
    }

    };


    int main(){
    Car a,b,c(12);
    a.displayValue();
    b.displayValue();
    c.displayValue();

    return 0;

    }