int pom_array_size(Node* node, int *array, int *n) {
    for (int i = 0; i < node->n; ++i) {
        array[*n] = node->keys[i];
        (*n)++;
    }

    if(node->leaf) return;
    for (int i = 0; i < node->n+1; ++i) {
        tmp_order(node->children[i],array,n);
    }
    return n;
}