题解 | #Fibonacci#

#include <iostream>
using namespace std;

int cal(int n){
    if(n == 0) return 0;
    else if(n == 1) return 1;
    else return cal(n - 1) + cal(n - 2);
}

int main() {
    int n;
    cin >> n;
    cout << cal( n );
    return 0;
}