#include <iostream>
#include<sys/types.h>
#include<unistd.h>
using namespace std;
int main() {
int pid = fork();
if (pid==0){
for (int i=0; i<3; i++) cout<<"Hello World.";
}
else{
sleep(10);
fork();
for(int j=0; j<2; j++) cout<<"Bye World.";
}
fork();
cout<<"Last fork.";
}
I2luY2x1ZGUgPGlvc3RyZWFtPgojaW5jbHVkZTxzeXMvdHlwZXMuaD4KI2luY2x1ZGU8dW5pc3RkLmg+CnVzaW5nIG5hbWVzcGFjZSBzdGQ7CgppbnQgbWFpbigpIHsKIAoJaW50IHBpZCA9IGZvcmsoKTsgCiAKICAgIGlmIChwaWQ9PTApeyAKICAgIGZvciAoaW50IGk9MDsgaTwzOyBpKyspIGNvdXQ8PCJIZWxsbyBXb3JsZC4iOwogCiAgICB9IAogCiAgICBlbHNleyAKICAgIHNsZWVwKDEwKTsgCiAgICBmb3JrKCk7IAogICAgZm9yKGludCBqPTA7IGo8MjsgaisrKSBjb3V0PDwiQnllIFdvcmxkLiI7CiAgICB9IAogICAgZm9yaygpOyAKICAgIGNvdXQ8PCJMYXN0IGZvcmsuIjsKfQ==