#include <bits/stdc++.h>

std::mt19937 s(std::chrono::steady_clock::now().time_since_epoch().count());
int64_t mul(int64_t x, int64_t y, int64_t mod) {
	return (__int128) x * y % mod;	
}
int64_t fastpow(int64_t x, int64_t p, int64_t mod) {
	int64_t r = 1;
	while (p) {
		if (p & 1) r = mul(r, x, mod);
		x = mul(x, x, mod);
		p >>= 1;
	}
	return r;
}

bool test(int64_t n) {
	if (n == 1) return false;
	if (n == 2 || n == 3) return true;
	if (n % 2 == 0) return false;
	int64_t a = n - 1, b = 0;
	while (a % 2 == 0) a >>= 1, ++b;
	for (int i = 0; i < 5; ++i) {
		int64_t x = s() % (n - 2) + 2;
		int64_t v = fastpow(x, a, n);
		if (v == 1) continue;
		bool ok = false;
		for (int j = 0; j < b; ++j) {
			if (v == n - 1) {
				ok = true;
				break;
			}
			v = mul(v, v, n);
		}
		if (!ok) return false;
	}
	return true;
}

int main() {
	int64_t n;
	while (scanf("%lld", &n) == 1)  {
		printf("%c\n", "NY"[test(n)]);
	}
}