#define  _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/wait.h>

void swap(int* x, int* y) {
    int z = (*x);
    (*x) = (*y);
    (*y) = z;
}

int main(int argc, char* argv[]) {
    int pipefd[2];
    int pipefd2[2] = {11111, 22901};

    pid_t pid = 0;
    for (int i = 1; i < argc; i++) {
        char* command = argv[i];
        if (i != argc - 1) pipe(pipefd);
        pid = fork();
        if (pid == 0) {
            if (i != 1) {
                close(pipefd2[1]);
                dup2(pipefd2[0], 0);
                close(pipefd2[0]);
            }
            if (i != argc - 1) {
                close(pipefd[0]);
                dup2(pipefd[1], 1);
                close(pipefd[1]);
            }
            execlp(command, command, NULL);
            exit(1);
        }
        else {
            swap(pipefd, pipefd2);
            swap(pipefd + 1, pipefd2 + 1);
            close(pipefd[0]);
            close(pipefd[1]);
        }
        wait(NULL);
    }
    return 0;
}