#include<bits/stdc++.h>
using namespace std;
string to_upper(string s){
    for (int i = 0; i < s.length(); i++)
	    if ('a' <= s[i] && s[i] <= 'z')
            s[i] -= 'a' - 'A';
	return s;
}
int main() {
    int N;
	cin >> N;
	string s[5005], s1, s2;
	getline (cin, s1);
	s2 = to_upper (s1);
    for (int i = 1; i <= N; i++)
    	s[i] = s[i - 2] + s[i - 1];
    cout << s[N];
	return 0;
}v