int f(int x){
int s=x%2;
while(x/=2)s+=x%2;
return s;
}

int g(int*a,int n){
int b[10001],i,j,s=0;
memcpy(b,a,n*4+4);
for(i=1;i<=n;i++){
if(!a[i])continue;
j=f(i);
if(i+j<=n&&!a[i+j])b[i+j]++,s++;
if(i-j>0&&!a[i-j])b[i-j]++,s++;
}
memcpy(a,b,n*4+4);
return s;
}

int main(){
int a[10001]={0,1},i=0,n;
scanf("%d",&n);
while(!a[n]&&g(a,n))i++;
printf("%d",a[n]?i+1:-1);
return 0;
}