#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/wait.h>

int main(int argc, char **argv) {
    if (argc != 3) {
        return 1;
    }
    int pipes[2];
    if (pipe(pipes) == -1) {
        return 1;
    }
    int pid = fork();
    if (pid == -1) {
        exit(1);
    }
    if (!pid) {
        dup2(pipes[1], 1);
        close(pipes[0]);
        close(pipes[1]);
        execlp(argv[1], argv[1], NULL);
        _exit(1);
    }
    pid = fork();
    if (pid == -1) {
        exit(1);
    }
    if (!pid) {
        dup2(pipes[0], 0);
        close(pipes[0]);
        close(pipes[1]);
        execlp(argv[2], argv[2], NULL);
        _exit(1);
    }
    close(pipes[0]);
    close(pipes[1]);
    wait(NULL);
    wait(NULL);
    return 0;
}