#include<cstdio>
#include<algorithm>
#include<random>
#include<ctime>
#define fo(i,x,y) for(int i = x;i <= y;++i)
#define ll long long
#define p 998244353
#define mp 1000033
using namespace std;
int n;ll a;
ll f[70];
mt19937_64 gen(time(0));
inline ll mul(ll x,ll y,ll n)
{
	ll z = (x * y - (ll)(1.0L * x / n * y) * n);
	if(z >= n) z -= n;if(z < 0) z += n;return z;
}
ll ksm(ll x,ll y,ll n)
{
	ll res = 1;
	for(;y;y >>= 1,x = mul(x,x,n)) if(y & 1) res = mul(res,x,n);
	return res;
}
bool wit(ll a,ll n)
{
	ll u = n - 1,t = 0;
	while(u + 1 & 1) u >>= 1,++t;
	a = ksm(a,u,n);
	fo(i,1,t)
	{
		ll A = mul(a,a,n);
		if(A == 1)
		{
			if(a == 1 || a == n - 1) return 1;
			return 0;
		}
		a = A;
	}
	return a == 1;
}
bool mr(ll n)
{
	if(n < 2) return 0;
	if(n == 2) return 1;
	fo(i,1,20)
	{
		ll a = gen() % (n - 2) + 2;
		if(wit(a,n) == 0) return 0;
	}
	return 1;
}
int main() {while(scanf("%lld",&n) != EOF) puts(mr(n) ? "Y" : "N");}