char *err;
        pagepair[npp][0] = strtoul(line, &err, 10);
        err += 1; // skip '|'
        pagepair[npp][1] = strtoul(line, &err, 10);
        npp++;
        line = strtok(NULL, "\n");
    }
    printf("first pagepair: %u and %u\n", pagepair[0][0], pagepair[0][1]);
    printf("last pagepair: %u and %u\n", pagepair[npp - 1][0], pagepair[npp - 1][1]);
    printf("%u\n", pagepair[0][0]);
    unsigned update[512], nupdates, maxupdates = 0;
    printf("got %u pairs\n", npp);
    while ((line = strtok(NULL, "\n")) != NULL) {
        nupdates = 0;
        // process line
    }
        char *err = line;
        for (;;) {
            update[nupdates++] = strtoul(err, &err, 10);
            if (*err == ',') err++;
            else break;
        }
        if (nupdates > maxupdates) maxupdates = nupdates;
    }
    printf("%u nax updates\n", maxupdates);
}
static size_t rcmap(unsigned size, unsigned row, unsigned col) {
    return row * (size + 1) + col;
}

static bool masat(char *data, unsigned size, unsigned row, unsigned col, int drow, int dcol) {
    int maxrow = (int)row + 3*drow;