Ricorsione con Fibonacci

#include <cstdlib>
#include <iostream>

using namespace std;

int fibonacci(int n) {
    if(n <=1)
        return 1;
    else
        return fibonacci(n - 1) + fibonacci(n - 2);
}

int main(int argc, char *argv[])
{
    int num;
    cout << "inserire N: " << endl;
    cin >> num;
    cout << "fibonacci: " << fibonacci(num) << endl;
    cout << "Press the enter key to continue ...";
    cin.get();
    cin.get();
    return EXIT_SUCCESS;
}