calculator c++

#include <iostream>
#include <cmath>

using namespace std;

int main() {

int num1, num2;
char op;


cout << "enter first number: ";
cin >> num1;
cout << "enter an operator: ";
cin >> op;
cout << "enter second number: ";
cin >> num2;
int result;

 if(op == '+'){
     cout << num1 + num2;
 }else if(op == '-'){
     cout << num1 - num2;
 }else if(op == '*'){
     cout << num1 * num2;
 }else if(op == '/' ){
     if(num2 =! 0){
         cout << "error" << endl;
     }
     cout << num1 / num2;
 }else{
     cout << "invalid operator" << endl;
 }

cout << result << endl;

return 0;

}