count = 0
category1 = 0
category2 = 0
category3 = 0
category4 = 0
ended = False

while not ended:
  mark=input("Enter a mark: ")
  mark=int(mark)

  if mark == -1:
    ended=True

  elif mark >= 70 and mark <= 100:
    category4 += 1
  elif mark >= 40 and mark <= 69:
    category3 += 1
  elif mark >= 30 and mark <=39:
    category2 +=1
  elif mark >= 0 and mark <=29:
    category1 +=1

  else:
     print("Wrong number. Try again.")

maxSize = max(category1,category2,category3,category4)

for i in range(maxSize, 0, -1):
    currentLine = ""
    for j in range(0,5):

        if j == 0:
            currentLine += "{0:2}|".format(i)

        else:
            categoryAmount = 0
            if j == 1:
                categoryAmount = category1
            elif j == 2:
                categoryAmount = category2
            elif j == 3:
                categoryAmount = category3
            else:
                categoryAmount = category4

            sign = " "
            if categoryAmount >= i:
                sign = "■"

            currentLine += " {:^11}".format(sign)

    print(currentLine)

print("   {0:^11} {1:^11} {2:^11} {3:^11}"
      .format("category1","category2","category3","category4"))