#include <bits/stdc++.h>

using namespace std;

long d[100];

long fibonacci(int n) {
	if (n < 3) return 1;
	if (d[n] != 0) return d[n];
	else d[n] = fibonacci(n - 1) + fibonacci(n - 2);
	return d[n];
}

int main() {
	int n;
	cout << "Nhap n: ";
	cin >> n;
	cout << "Ket qua: " << fibonacci(n);
	return 0;
}