18 lines
408 B
Python
18 lines
408 B
Python
'''
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((a - 1) ** n + (a + 1) ** n) % (a ** 2) =
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2an % (a ** 2), if n is odd; 2, if n is oven
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'''
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def pre_odd(q):
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n = int(q)
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if n == q:
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return n - (1 + n % 2)
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else:
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return n - (1 - n % 2)
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def r_max(a):
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return max(map(lambda n: 2 * a * n % (a ** 2),
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map(lambda x: pre_odd(x), [a / 2, a, 3 * a / 2, 2 * a])))
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print(sum(map(lambda x: r_max(x), range(3, 1001))))
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