C++

#include<string>
#include<algorithm>
using namespace std;
#define MAX 100
int dp[21];
void initDpArray() {
	dp[1] = 1;
	dp[2] = 2;
	for (int i = 3; i < 21; i++) {
		dp[i] = dp[i - 1] + dp[i - 2];
	}
}
int main() {
	int N;
	initDpArray();
	while (cin >> N) {
		cout << dp[N] << endl;
	}

	return 0;
}