#include <stdio.h>
#include <stdlib.h>

int main()
{
    FILE *f,*g;
    f=fopen("fact.in","r");
    g=fopen("fact.out","w");
    int n;
    fscanf(f,"%d",&n);
    if(n==0)
    fprintf(g,"%d\n",1);
    else
    fprintf(g,"%d\n",-1);
    return 0;
}