# a = input("hay nhap vao hon 2 ki tu: ")

# while len(a) < 2:
#     a = input("it hon 2 ki tu, ban nhap lai di:")

# print(a)

# is_digit = 1
# while is_digit > 0:
#     age = input("nhap tuoi cua ban:")
#     is_digit = 0
#     for c in age:
#         if 48 <= ord(c) and ord(c) <= 57:
#             print(c, "la so")
#         else:
#             print(c, "khong la so")
#             is_digit = is_digit + 1

# print("tuoi cua ban la ", age)

#su dung while True de lam bai nay