50分递归求助！！！悬关

#include <bits/stdc++.h>
using namespace std;
unsigned n;
unsigned A(unsigned x){
    if(x==1){
        return 1;
    }else if(x==2){
        return 2;
    }
    return A(x-1)+A(x-2);
}
int main (){
    cin>>n;
    cout<<A(n);
    return 0;
}