#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/wait.h>

int
execute(char *arg)
{
    int status = 0;
    pid_t pid = fork();
    if (pid == -1) {
        return 0;
    } else if (!pid) {
        execlp(arg, arg, NULL);
        _exit(1);
    }

    wait(&status);

    return (WIFEXITED(status) && !WEXITSTATUS(status));
}

int
main(int argc, char *argv[])
{
    return ((!execute(argv[1]) || !execute(argv[2])) && !execute(argv[3]));
}