Addition of complex numbers using c++

#include<iostream>
#include<stdlib.h>
using namespace std;
class COMPLEX
{
        float real,imag;

        public:
                void getinfo();
                COMPLEX add(float,COMPLEX);
                COMPLEX add(COMPLEX,COMPLEX);
                void display(COMPLEX,COMPLEX);
};


void COMPLEX::getinfo()
{
cout<<"\nenter real and imaginary part for complex no\n";
cin>>real>>imag;
}

COMPLEX COMPLEX::add(float a,COMPLEX s1)
{
COMPLEX s3;
s3.real=a+s1.real;
s3.imag=s1.imag;
return s3;
}

COMPLEX COMPLEX::add(COMPLEX s1,COMPLEX s2)
{
COMPLEX s4;
s4.real=s1.real+s2.real;
s4.imag=s1.imag+s2.imag;
return s4;
}

void COMPLEX::display(COMPLEX s3,COMPLEX s4)
{
cout<<"\nsum = "<<s3.real<<" +i "<<s3.imag<<endl;
cout<<"\nsum = "<<s4.real<<" +i "<<s4.imag<<endl;
}

int main()
{
        COMPLEX c1,c2,c3,c4,c5;
        float a;
        system("clear");
        c1.getinfo();
        c2.getinfo();
        cout<<"enter an integer no\n";
        cin>>a;
        c3=c3.add(a,c1);
        c4=c4.add(c1,c2);
        c5.display(c3,c4);
        return 1;
}