##Find the unique positive integer whose square has the form 1_2_3_4_5_6_7_8_9_0,
##where each “_” is a single digit.


def isresult(n):
    s = str(n * n)
    return len(s) == 19 and all(s[i * 2] == str(i + 1) for i in range(9))


def p206():
    for i in range(10000000, 14142135 + 1):
        if i % 10000 == 0:
            print(i)
        if isresult(i * 100 + 30):
            return i * 100 + 30
        elif isresult(i * 100 + 70):
            return i * 100 + 70


print(p206())
