Add '\' to several parts of "Hello World"

#include "stdio.h"

int main(int argc, char *argv[])
{
  printf("Hello, world!\n");
  printf("Hell\o, world!\n");
  printf("Hello, \world!\n");
  printf("Hello, world!\\n");

  return 0;
}

Output:

Hello, world!
Hello, world!
Hello, world!
Hello, world!\n

gcc errors:

main.c:6:10: warning: unknown escape sequence '\o'
main.c:7:10: warning: unknown escape sequence '\w'

Notes:

Notice the abilty to remove the escape slashes by the compiler. It really does make our life easier. ;)