tsk 3

import math
# 21 (3*x - 6, 3*x + 99) -> 105 - 5
# 3x == 6+21k
# x = 2+7k -> 9, 16, 23.... 100
print(math.gcd((100+7*2)*3-6, (100+7*2)*3+99), 100+7*2)

for i in range(101, 1000):
    x = i
    l = 3*x - 6
    m = 3*x + 99
    while l != m:
        if l > m:
            l -= m
        else:
            m -= l
    if m == 21:
        print(i)
        break