#include <iostream>
using namespace std;

int main()
{
  int n, locate, bitcount, movenum;
  int road[10000], through[10000];
  cin >> n;
  locate=0;
  movenum=99999;
  for( int i=0; i<n; ++i )through[i]=0;
  for( int i=0; i<n; ++i )
  {
      if( n==locate+1 )
      {
        if(movenum>i+1)movenum=i+1;
      }

      road[i]=locate;
      through[locate]=1;
      if(0==through[locate])for(int j=locate+1; j>1; j>>=1)through[locate]+=j&1;
      if(n-1<locate+through[locate] || 0<through[locate+through[locate]])
      {
        if(0>locate-through[locate] || 0<through[locate-through[locate]])
        {
          if(1==road[i-1])i=n;
          else{ locate=road[i-1]; i--; }
        }
        else locate-=through[locate];
      }
      else locate+=through[locate];
  }
  if(movenum>10000)movenum=-1;
  cout << movenum << endl;
  return 0;
}