Stringzz

The program take any length of input from stdin, the input buffer is initially a pointer to NULL, will be allocated a pointer to a new buffer by getline.
The flag is stored in heap.
printMessage1 to call printMessage2, which calls printMessage3 to print the input with printf, as it simply pass whatever we input to printf, we can use %n$s to jump to the nth layer of stack to print the string.