include <stdio.h>

int main() {

int n, a = 2, b = 0;
scanf("%d", &n);
while (a <= n - 1) {
	if (n % a == 0) {
		b = b + 1;
	}
	a = a + 1;
}
if (b != 0) {
	printf("-1");
} else {
	printf("1");
}
return 0;

}