Program C++ Penjumlahan dan perkalian(hanya menggunakan operator +)

#include <iostream>
#include <conio.h>
using namespace std;
int tambah (int a,int b) {
  int x;
  x=a+b;
  return x;
}

int kali (int a,int b){
  int y;
  for (int i=1; i<=b; i++) {
  y=y+a;
}
  return y;
}
main (){
  int a,b,x,y;

  cout<<"nilai a : ";
  cin>>a;
  cout<<"nilai b : ";
  cin>>b;
  x=tambah(a,b);
  cout<<"hasil tambah : "<<x<<endl;
  y=kali(a,b);
  cout<<"hasil kali : "<<y<<endl;

getch (); 
}

Outputnya :