include<stdio.h>

int main() {

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

}