#include <stdio.h>

// variante de tiparire a unui numar in baza 2

// recursiv, prin impartire succesiva la 2
void printbits(unsigned n)
{
  if (n > 1) printbits(n / 2);
  putchar(n % 2 + '0');
}

// la fel, inlocuind operatiile aritmetice cu operatii pe biti
void printbits2(unsigned n)
{
  if (n > 1) printbits2(n >> 1);
  putchar((n & 1) + '0');
}

// tipareste pe un numar dat de biti
void printkbits(unsigned n, unsigned k)
{
  if (k > 1) printkbits(n / 2, k - 1);
  putchar(n % 2 + '0');
}

// tipareste toti bitii, deplasand o masca la dreapta
void printallbits(unsigned n)
{
  unsigned mask = ~(~0u >> 1);
  do {
    putchar((n & mask) ? '1' : '0');
    mask >>= 1;
  } while (mask);
}

// tipareste toti bitii, deplasand numarul la stanga si testand bitul de semn
void printallbits2(unsigned n)
{
  unsigned bits = 8*sizeof(n);
  while (bits--) {
    putchar((int)n < 0 ? '1' : '0');
    n <<= 1;
  }
}

// tipareste bitii in ordine inversa (pe numar minim de biti)
void printrevbits(unsigned n)
{
  do {
    putchar((n & 1) + '0');
    n >>= 1;
  } while (n);
}

// citeste un numar introdus in baza 2
unsigned readbase2(void)
{
  unsigned r = 0;
  int c = getchar();
  while (c == '0' || c == '1') {
    r = (r << 1) | (c - '0');
    c = getchar();
  }
  ungetc(c, stdin);
  return r;
}

int main(void)
{
  printbits(19);
  putchar('\n');
  printbits2(19);
  putchar('\n');
  printkbits(19, 8*sizeof(19));
  putchar('\n');
  printallbits(19);
  putchar('\n');
  printallbits2(19);
  putchar('\n');
  printrevbits(19);
  putchar('\n');
  printallbits(readbase2());
  putchar('\n');
  return 0;
}