//example2.cpp
// Hello world program with more advanced IO
#include <stdio.h>
#include <unistd.h>
#include <string.h>
main()
{
  char ch;
  char outbuf[20];
  int i, j;

  i = 0;
  read(0, &ch, 1);
  while ((ch <= '9') && (ch >='0')) {
    i = i * 10 + ch - '0';
    read(0, &ch, 1);
  }

  sprintf(outbuf, "%d\n", i);
  write(1, outbuf, strlen(outbuf));
}