#include<bits/stdc++.h>
using namespace std;
int k,k1,k2,n;
int main()
{
	cin>>n;
	k=1;
	k1=1;
	while(k2<n)
	{
		k2=k+k1;
		k=k1;
		k1=k2;
	}
	if(k2==n) cout<<"YES";
		else cout<<"NO";
}