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

int main(int argc, char *argv[])

{

    int pfd[2];
    int pfd_2[2];
    int x=0, y=0;
    pid_t cpid;
    struct liczby
    {
        int x;
        int y;
    };

    struct liczby bufor_dz, bufor_o;
    bufor_dz.x=0;
    bufor_dz.y=0;
    bufor_o.x=0;
    bufor_o.y=0;
    int suma=0;
    int buf;
    int suma_dziecko=0;

    if (pipe(pfd) == -1) { perror("pipe"); exit(EXIT_FAILURE); }
    if (pipe(pfd_2) == -1) { perror("pipe_2"); exit(EXIT_FAILURE); }
    cpid = fork();
    if (cpid == -1) { perror("fork"); exit(EXIT_FAILURE); }
    if (cpid == 0)
    {

        close(pfd[0]);


        scanf("%d %d", &bufor_dz.x, &bufor_dz.y);
        write(pfd[1], &bufor_dz, sizeof(struct liczby));

    close(pfd_2[1]);
        read(pfd_2[0], &suma_dziecko, sizeof(struct liczby));
        printf("%d\n", suma_dziecko);

        _exit(EXIT_SUCCESS);

    }
    else
    {

        close(pfd[1]);
        read(pfd[0], &bufor_o, sizeof(struct liczby));
        suma=bufor_o.x+bufor_o.y;


    close(pfd_2[0]);
        write(pfd_2[1], &suma, sizeof(int));

        wait(NULL);

        exit(EXIT_SUCCESS);

    }

}