import math
def custom_add(a, b):
list_a = [int(digit) for digit in str(a)[::-1]]
list_b = [int(digit) for digit in str(b)[::-1]]
max_len = max(len(list_a), len(list_b))
list_a += [0] * (max_len - len(list_a))
list_b += [0] * (max_len - len(list_b))
carry = 0
result = []
for i in range(max_len):
total = list_a[i] - list_b[i] + carry
carry = total // 10
result.append(total % 10)
if carry > 0:
result.append(carry)
return int(''.join(map(str, result[::-1])) if result else 0)
answer = []
squrt = float(2)
piece = 5
for i in range(piece):
for k in range(10):
if (k * 20) ** 2 > squrt:
answer.append(str(k - 1))