#include <ctype.h>
#include <stdio.h>

// converteste din cod ascii in valoare cifra (0-15)
unsigned digval(unsigned c)
{
  return isdigit(c) ? c - '0' : toupper(c) - 'A' + 10;
}

unsigned readnat(void)
{
  unsigned r = 0;
  int c;
  while (isdigit(c = getchar()))
    r = 10*r + c - '0';
  ungetc(c, stdin);
  return r;
}

unsigned readhex(void)
{
  unsigned r = 0;
  int c;
  while (isxdigit(c = getchar()))
    r = 16*r + digval(c);
  ungetc(c, stdin);
  return r;
}

// converteste din cifra in cod ASCII
int hexascii(unsigned val)
{
  return val < 10 ? '0' + val : 'a' - 10 + val;
}

void printhex(unsigned n)
{
  if (n > 15)
    printhex(n / 16);
  putchar(hexascii(n % 16));
}

int main(void)
{
  // printf("%u\n",readhex());
  printhex(readnat());
  putchar('\n');
  return 0;
}