Arithmatic operation in c++ using class.

// Arithmatic operation on class
#include<iostream>
#include<stdlib.h>
#include<stdio.h>
using namespace std;
class abc{
	int a,b,c;
	public:
	void set()
	{
		cout<<"\nEnter a number  :";cin>>b;
		cout<<"Enter a second number :";cin>>c;
		cout<<endl<<endl;
	}
	void get(int a){
		int f=a;
	
		if(f==1){
			set();
			cout<<"\nddition of two number is :"<<b+c<<endl;
		}
		if(f==2){
			set();
			cout<<"\nminus of two number is :"<<b-c<<endl;	
		}
		if(f==3){
			set();
			cout<<"\nmultiply of two number is :"<<b*c<<endl;		
		}
		if(f==4){
			set();
			cout<<"\ndivision of two number is:"<<b/c;
		}

	}
	
};

int main(){
	
	abc st;
	system("clear");
	int x,a;
	x:
	cout<<"1.addition"<<endl;
	cout<<"2.minus"<<endl;
	cout<<"3.multiply"<<endl;
	cout<<"4.divion"<<endl;
	cout<<"Enter your choice  :";
	cin>>a;
	st.get(a);
	cout<<"\n\nagain tap 1";
	int ag;	
	cin>>ag;
	if(ag=1){
		system("clear");
		goto x;
	}
}

1.addition
2.minus
3.multiply
4.divion
Enter your choice  : 1
Enter a number : 10
Enter a second number :20

Addition of two number is : 30