include <bits/stdc++.h>

using namespace std;

int main() {

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

}
if (c == 0) {
	printf("1");
} else {
	printf("-1");
}
return 0;

}