error: 1 duplicate symbol for architecture x86_64

I have been trying to use xcode for school, and everey time i run the code, it gives me that error... this is the code that i have been using...


#include <iostream>

using namespace std;

int main() {
  int a, b, P, A, d;
  cin >> a >> b;
  d = 50;
  P = 2 * a + 2 * b;
  A = a * b;
  cout << P << A << d;
}