#include <iostream>
#include <string>
#include <algorithm>

std::string DecimalAsBinary(unsigned int number);

int main()
{
  std::cout << DecimalAsBinary(19);
  return 0;
}

std::string DecimalAsBinary(unsigned int number)
{
  std::string result, mod_string;
  while (number)
    {
      mod_string = (number & 1) + '0';
      number >>= 1;
      result = result + mod_string;
    }
  std::reverse(result.begin(), result.end());
  return result;
}