how to wait on children and grandchildren processes

Question

  if(pid==0){ //child1
    pid = fork();
    if(pid==0){//child1 of child1
        print("I am child 1 of child 1");
    }
    else{//child1
        pid = fork();
        if(pid==0){//child 2 of child 1
            print("I am child 2 of child 1");              
        }
        else{//child 1 waits on children
            print("I am child 1");           
        }
    }
}
else{ //parent
    pid = fork();       
    if (pid==0){//child2
        pid = fork();
        if(pid==0){//child1 of child 2
            print("I am child 1 of child 2");             
        }
        else{//child2 
            pid = fork();
            if(pid==0){//child2 of child 2
               print("I am child 2 of child 2");              
            }
            else{//child 2 waits on children 
                 print("I am child 2");
                int sum2 = sum(secondHalf,count);                 
            }
        }
    }
    else{//parent
       //i want to wait here for children and grandchildren process
    }
}

Hey guys I'd like to wait on all my child processes and grand child processes before proceeding on with the parent. I tried giving each process a unique id and waitpiding but the following did not work either

pid_t child1,child2,child1ofchild1,child2ofchild1,child1ofchild2,child2ofchild2;
int status;
child1 = fork();
if(child1==0){ //child1
    child1ofchild1 = fork();
    if(child1ofchild1==0){//child1 of child1
        print("I am child 1 of child 1");

        exit(1);
    }
    else{//child1
        child2ofchild1 = fork();
        if(child2ofchild1==0){//child 2 of child 1
            print("I am child 2 of child 1");

            exit(1);
        }
        else{//child 1 waits on children
            print("I am child 1");

            exit(1);
        }
    }
}
else{ //parent
    child2 = fork();        
    if (child2==0){//child2
        child1ofchild2 = fork();
        if(child1ofchild2==0){//child1 of child 2
            print("I am child 1 of child 2");
            exit(1);
        }
        else{//child2 
            child2ofchild2 = fork();
            if(child2ofchild2==0){//child2 of child 2
               print("I am child 2 of child 2");

               exit(1);
            }
            else{//child 2 waits on children 
                 print("I am child 2");

            }
        }
    }
    else{//parent
        waitpid(child1, &status, WNOHANG|WUNTRACED);
        waitpid(child1ofchild1, &status, WNOHANG|WUNTRACED);
        waitpid(child2ofchild1, &status, WNOHANG|WUNTRACED);
        waitpid(child2, &status, WNOHANG|WUNTRACED);
        waitpid(child1ofchild2, &status, WNOHANG|WUNTRACED);
        waitpid(child2ofchild2, &status, WNOHANG|WUNTRACED);
        print("got here");
    }
}

essentially I'd like to create a process tree which the main parent creates two children and their children create two children. I set it up this way because id like to have control over what happens in each specific process. For some reason I cannot wait for all the children and grandchildren processes to end before continuing on with the main process. Can anyone help me?