#include <iostream>

int a(int n, int a0 = 0, int a1 = 1)
{
    if(n <= 0)
        return a0;
    return a(n-1, a1, a0+a1);
}

int main()
{
    using namespace std;
    for(int i = 0; i < 10; ++i)
        cout << "a(" << i << ") = " << a(i) << endl;
    return 0;
}