void ListMerge(sepList A, sepList B, sepList C) {
    int i, j, k;
    i = j = k = 0;
    while (i < n && j < m) {
        if (A[i].key <= B[j].key) {
            C[k] = A[i];
            i++;
        }
        else {
            C[k] = B[j];
            j++;
        }
        k++;
    }
    while (i < n) {
        C[k] = A[i];
        i++;
        k++;
    }
    while (j < m) {
        C[k] = B[j];
        j++;
        k++;
    }
}