int function(char **a, int n)
{
    int i, j, counter = 0, will_be_removed = 0;

    for( i = 1; i<n; i++ )
    {
        if( strpbrk(a[i], a[i - 1]) )
        {
            will_be_removed++;
            continue;
        }
        if( will_be_removed )
        {
            for( j = 0; j<will_be_removed; j++)
            {
                free(a[i - 1 - j]);
            }
            will_be_removed = 0;
        }
        a[counter] = a[i];
        counter++;
    }
    return counter;
}