#include <stdio.h>
#include <string.h>
char n[20];
int main()
{
    scanf("%s",&n);
    int ok=2,scs=strlen(n);
    if((int)(n[scs-1]-'0')%2)ok=1;
    if(scs%2==1&&ok==1)printf("1");
    else if(scs%2==0&&ok==2)printf("0");
    else printf("-1");
}