#include <cstdio>
#include <cstdlib>
#include <sys/types.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <unistd.h>
#include <iostream>
using namespace std;

int x;

void work(char c)
{
  x = c;
  for (int i=0; i < 20; ++i) {
    for (int j=0; j < 10000000; ++j);
    cout << c << flush;
  }
  cout << " " << c << " " << x << " DONE " << endl;
}

int main()
{
  pid_t pid; // process id

  pid = fork(); // spawn child process

  if (pid < 0) return pid; // error
  
  if (pid == 0) { // child
    work('A');
    return 0;
  }

  // parent process
  work('B');
  waitpid(pid, 0, 0); // wait for child
  return 0;
}