#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/wait.h>
#include <cstdio>
#include <cstdlib>
#include <cstring>

struct MsgStruct {
    long mtype;
    char mtext[1024];
};

int main() {
    key_t key = ftok("/tmp", 'a');
    int msgid = msgget(key, IPC_CREAT | 0666);
    if (fork() == 0) {
        char a[64][64];
        for (int i = 0; i < 64; i++)
            for (int j = 0; j < 64; j++)
                a[i][j] = i < 32 ? (j < 32 ? 'a' : 'b') : (j < 32 ? 'c' : 'd');
        struct MsgStruct mgb;
        mgb.mtype = 1;
        int k = 0;
        for (int i = 0; i < 32; i++) for (int j = 0; j < 32; j++) mgb.mtext[k++] = a[i][j];
        msgsnd(msgid, &mgb, sizeof(mgb), 0);
        k = 0;
        for (int i = 0; i < 32; i++) for (int j = 32; j < 64; j++) mgb.mtext[k++] = a[i][j];
        msgsnd(msgid, &mgb, sizeof(mgb), 0);
        k = 0;
        for (int i = 32; i < 64; i++) for (int j = 0; j < 32; j++) mgb.mtext[k++] = a[i][j];
        msgsnd(msgid, &mgb, sizeof(mgb), 0);
        k = 0;
        for (int i = 32; i < 64; i++) for (int j = 32; j < 64; j++) mgb.mtext[k++] = a[i][j];
        msgsnd(msgid, &mgb, sizeof(mgb), 0);
        exit(1);
    }
    if (fork() == 0) {
        struct MsgStruct mgb;
        mgb.mtype = 2;
        strcpy(mgb.mtext, "ijkl");
        msgsnd(msgid, &mgb, sizeof(mgb), 0);
        strcpy(mgb.mtext, "mnop");
        msgsnd(msgid, &mgb, sizeof(mgb), 0);
        exit(2);
    }
    if (fork() == 0) {
        char a[64][64];
        struct MsgStruct mgb;
        msgrcv(msgid, &mgb, sizeof(mgb), 1, 0);
        int k = 0;
        for (int i = 0; i < 32; i++) for (int j = 0; j < 32; j++) a[i][j] = mgb.mtext[k++];
        msgrcv(msgid, &mgb, sizeof(mgb), 1, 0);
        k = 0;
        for (int i = 0; i < 32; i++) for (int j = 32; j < 64; j++) a[i][j] = mgb.mtext[k++];
        msgrcv(msgid, &mgb, sizeof(mgb), 1, 0);
        k = 0;
        for (int i = 32; i < 64; i++) for (int j = 0; j < 32; j++) a[i][j] = mgb.mtext[k++];
        msgrcv(msgid, &mgb, sizeof(mgb), 1, 0);
        k = 0;
        for (int i = 32; i < 64; i++) for (int j = 32; j < 64; j++) a[i][j] = mgb.mtext[k++];
        for (int i = 0; i < 64; i++) {
            for (int j = 0; j < 64; j++) printf("%c", a[i][j]);
            printf("\n");
        }
        exit(3);
    }
    if (fork() == 0) {
        struct MsgStruct mgb;
        msgrcv(msgid, &mgb, sizeof(mgb), 2, 0);
        printf("p4 received %s\n", mgb.mtext);
        msgrcv(msgid, &mgb, sizeof(mgb), 2, 0);
        printf("p4 received %s\n", mgb.mtext);
        exit(4);
    }
    wait(NULL);
    msgctl(msgid, IPC_RMID, NULL);
    return 0;
}