include <bits/stdc++.h>

using namespace std;

int main() {

int a = 1, i, n, c = 0;
scanf("%d", &n);
for (int i = 2; i <= n - 1; i++) {
	if (n % i == 0) {
		c++;
	}
}
if (c == 0)
	printf("1");
else
	printf("-1");

return 0;

}