#include <stdio.h>
#include <pthread.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <math.h>
#include <signal.h>

int count = 0;
int mode = 0;
const uint32_t adress_mask = 1073676288;
const uint32_t host_mask = 16383;

uint32_t is_category_b(uint32_t num) {
    if (num >> 30 == 2) {
        return 1;
    }
    return 0;
}

uint32_t get_adress(uint32_t num) {
    return (num & adress_mask) >> 16;
}

uint32_t get_host(uint32_t num) {
    return num & host_mask;
}

void signal_handler(int signo) {
    if (count == 4) {
        exit(0);
    }
    if (signo == SIGUSR1) {
        mode = 1 - mode;
        ++count;
    } else if (signo == SIGUSR2) {
        uint32_t num;
        scanf("%o", &num);
        if (is_category_b(num)) {
            if (mode == 0) {
                printf("%d\n", get_adress(num));
                fflush(stdout);
            } else if (mode == 1) {
                printf("%d\n", get_host(num));
                fflush(stdout);
            }
        } else {
            printf("%d\n", 0);
        }
    }
}

int main(int argc, char ** argv) {
    struct sigaction sa = {};
    sa.sa_handler = signal_handler;
    sa.sa_flags = SA_RESTART;
    sigaction(SIGUSR1, &sa, NULL);
    sigaction(SIGUSR2, &sa, NULL);
    printf("%d\n", getpid());
    fflush(stdout);
    while (42) {
    }
}