• #include <bits/stdc++.h>
  using namespace std; 
  int x;
  int a[35];
  int main(){
  	while(cin >> x){
  		a[1] = 1;
  		a[2] = 2;
  		for(int i=3;i<=x;i++){
  			a[i]=a[i-1]+a[i-2];
  		} 
  		cout << a[x] << endl;
  	}
  	return 0;
  }
  

  Copy

#include <bits/stdc++.h>
using namespace std; 
int x;
int a[35];
int main(){
	while(cin >> x){
		a[1] = 1;
		a[2] = 2;
		for(int i=3;i<=x;i++){
			a[i]=a[i-1]+a[i-2];
		} 
		cout << a[x] << endl;
	}
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int n;
int a[35];
int f(int x)
{
	if(x==1)
		return 1;
	if(x==2)
		return 2;
	return f(x-1)+f(x-2);
} 
int main()
{
	while(cin>>n){
		cout<<f(n)<<endl;
	}
	return 0;
}