8.12

8 lines

                        c
                    +-------+---------+
                    |    "hello"   "hello"
                    |    
                c   |   p
            +-------+-------+---------+
            |     fork   "hello"   "hello"
            |
            |           c
            |       +-------+---------+
            |       |    "hello"   "hello"
            |       |    
            |   p   |   p    
     +------+-------+-------+---------+
    main  fork    fork   "hello"   "hello"