15 lines
439 B
Python
15 lines
439 B
Python
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import sys, re
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# Возвращает абсолютно наименьший вычет числа a по модулю числа b
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def v(a, b):
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r1 = a % b
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r2 = r1 - b
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return r1 if abs(r1) < abs(r2) else r2
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def solve(a, p):
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stop_i = (p-1)>>1 + 1
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cnt = sum(1 for i in range(1, stop_i) if v(a*i, p) < 0)
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return pow(-1, cnt)
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f = re.fullmatch(r'(\d+)/(\d+)', sys.argv[1]).groups()
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print(solve(int(f[0]), int(f[1])))
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