#include <unistd.h>
#include <stdlib.h>
#include <wait.h>
#include <fcntl.h>

int main(int argc, char *argv[])
{
    int fd[2];
    int st;
    pipe(fd);
    pid_t pid = fork();
    if (pid == -1) {
        exit(1);
    } else if (pid == 0) {
        close(fd[0]);
        dup2(fd[1], 1);
        close(fd[1]);
        execlp(argv[1], argv[1], NULL);
        _exit(1);
    }
    close(fd[1]);
    int fd1[2];
    pipe(fd1);
    pid_t pid1 = fork();
    if (pid1 == -1) {
        exit(1);
    } else if (pid1 == 0) {
        dup2(fd[0], 0);
        dup2(fd1[1], 1);
        close(fd[0]);
        close(fd1[1]);
        close(fd1[0]);
        if (fork() == 0) {
            int f = open(argv[5], O_CREAT | O_TRUNC | O_WRONLY, 0600);
            dup2(f, 2);
            close(f);
            execlp(argv[2], argv[2], NULL);
            _exit(1);
        } else {
            wait(&st);
            if (WIFEXITED(st) && !WEXITSTATUS(st)) {
                if (fork() == 0) {
                    execlp(argv[3], argv[3], NULL);
                    _exit(1);
                } else {
                    wait(0);
                }
            }
        }
        exit(0);
    }
    close(fd[0]);
    close(fd1[1]);
    pid_t pid2 = fork();
    if (pid2 == -1) {
        exit(1);
    } else if (pid2 == 0) {
        dup2(fd1[0], 0);
        close(fd1[0]);
        execlp(argv[4], argv[4], NULL);
        _exit(1);
    }
    close(fd1[0]);
    while (wait(0) != -1);
    exit(0);

}