def counting(arr):
    frequency = [0 for i in range(100)]
    for num in arr:
        frequency[num] += 1
    return frequency

def countingSort(arr):
    frequency = counting(arr)
    sortedarr = []
    for i in range(len(frequency)):
        for j in range(frequency[i]):
            sortedarr.append(str(i))
    return sortedarr