#include <iostream>
#include <sstream>
#include <string>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <vector>
#include <array>
#include <map>
#include <bitset>
#include <memory>
#include <algorithm>
#include <utility>

namespace Util
{

std::vector<std::string> Split(const std::string& str, const char delim);
std::string Itos(const int value);
std::string Ftos(const double value);
int Stoi(const std::string& buf);
double Stof(const std::string& buf);
std::vector<int> ConvertInt(const std::vector<std::string>& buffers);
std::vector<double> ConvertDouble(const std::vector<std::string>& buffers);

}// namespace Util


namespace Node
{
enum NodeIndex
{
	Front = 0,
	Back,
	Size,
};
}

struct Element
{
	std::array<int, Node::Size> node = { {-1, -1} };
};

int Search(const std::vector<Element>& root, std::vector<int>& memo, const int index, const int step)
{
	static int minStep = static_cast<int>(root.size()) + 1;

	if(index == static_cast<int>(root.size()) - 1)
	{
		if(step < minStep)
		{
			minStep = step;
		}
	}

	if(Node::Size <= memo[index])
	{
		return minStep;
	}

	if(memo[index] <= 0)
	{
		++memo[index];

		if(root[index].node[Node::Front] != -1)
		{
			Search(root, memo, root[index].node[Node::Front], step + 1);
		}
	}

	if(memo[index] <= 1)
	{
		++memo[index];

		if(root[index].node[Node::Back] != -1)
		{
			Search(root, memo, root[index].node[Node::Back], step + 1);
		}
	}

	return minStep;
}

int main()
{
	// 入出力の速度向上
	std::cin.tie(0);
	std::ios::sync_with_stdio(false);

	std::string buf;
	std::vector<std::string> buffers;

	std::vector<int> mass;
	std::vector<Element> root;
	std::vector<int> memo;

	std::getline(std::cin, buf);
	mass.resize(Util::Stoi(buf));

	for(int cur = 0; cur < static_cast<int>(mass.size()); ++cur)
	{
		mass[cur] = std::bitset<32>(cur + 1).count();
	}

	root.resize(mass.size());
	for(int cur = 0; cur < static_cast<int>(mass.size()); ++cur)
	{
		if(cur + mass[cur] < static_cast<int>(mass.size()))
		{
			root[cur].node[Node::Front] = cur + mass[cur];
		}

		if(0 <= cur - mass[cur])
		{
			root[cur].node[Node::Back] = cur - mass[cur];
		}
	}

	memo.resize(mass.size(), 0);

	int minStep = Search(root, memo, 0, 1);
	printf("%d\n", static_cast<int>(root.size()) < minStep ? -1 : minStep);



	return 0;
}


namespace Util
{

std::vector<std::string> Split(const std::string& str, const char delim)
{
	std::istringstream iss(str);
	std::vector<std::string> ret;
	std::string tmp;

	while(std::getline(iss, tmp, delim))
	{
		ret.push_back(tmp);
	}

	return ret;
}

std::string Itos(const int value)
{
	std::ostringstream ostream;
	ostream << value;
	return ostream.str();
}

std::string Itof(const double value)
{
	std::ostringstream ostream;
	ostream << value;
	return ostream.str();
}

int Stoi(const std::string& buf)
{
	return std::atoi(buf.c_str());
}

double Stof(const std::string& buf)
{
	return std::atof(buf.c_str());
}

std::vector<int> ConvertInt(const std::vector<std::string>& buffers)
{
	std::vector<int> ret(buffers.size());

	for(int cur = 0; cur < static_cast<int>(ret.size()); ++cur)
	{
		ret[cur] = Stoi(buffers[cur]);
	}

	return ret;
}

std::vector<double> ConvertDouble(const std::vector<std::string>& buffers)
{
	std::vector<double> ret(buffers.size());

	for(int cur = 0; cur < static_cast<int>(ret.size()); ++cur)
	{
		ret[cur] = Stof(buffers[cur]);
	}

	return ret;
}

}// namespace Util