D = {}
    arr = sorted(arr)
    mini = 10e6
    for i in range(len(arr) -1):
        diff = arr[i+1] - arr[i]
        if diff < mini: 
            mini = diff
            D[diff] = [arr[i+1], arr[i]]
        elif diff == mini:
            D[diff].extend([arr[i+1], arr[i]])
    
    result = sorted(D[mini])       
    return result