#include <library.h>

void print_in_octal(int N, unsigned int mask, int shift)
{ if (mask == 0)
    return;
  const int digit = (N & mask) >> shift;
  cout << digit;
  print_in_octal(N, mask >> 3, shift - 3); }

void print_in_octal_no_zeros(int N, unsigned int mask, int shift)
{ if (mask == 0)
  { cout << "0";
    return; }
  const int digit = (N & mask) >> shift;
  if (digit == 0)
    print_in_octal_no_zeros(N, mask >> 3, shift - 3);
  else
  { cout << digit;
    print_in_octal(N, mask >> 3, shift - 3); } }

void print_in_octal(unsigned int N)
{ const int first = (N & 0xC0000000) >> 30;
  if (first == 0)
    print_in_octal_no_zeros(N, 0x38000000, 27);
  else
  { cout << first;
    print_in_octal(N, 0x38000000, 27); } }

int main()
{ cout << "Enter a number: ";
  const int x = read_int();
  print_in_octal(x);
  cout << "\n"; }