int get(int a[], int len)
{
    int mid = 100;
    int row = 0;
    int rank = 0;
    for (row = 0; row < len; row++)
    {
        for (rank = row + 1; rank < len; rank++)
        {
            if (abs(a[rank] - a[row]) < mid)
            {
                mid = abs(a[rank] - a[row]);
            }
        }
    }
    return mid;
}