60pts，WA后4个，球调！！

#include <bits/stdc++.h>

using namespace std;

int n;
long long f[60];

inline long long g(const int &x) {
	if (f[x] != 0) {
		return f[x];
	}
	if (x <= 1) {
		return 1;
	}
	f[x] = g(x - 1) + g(x - 2);
	return f[x];
}

int main() {
	scanf ("%d", &n);
	memset(f, 0, sizeof(f));
	printf ("%lld\n", g(n));
	return 0;
}

orz