20 lines
396 B
Python
20 lines
396 B
Python
import sys
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sys.stdin = open("input.txt", "r")
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sys.stdout = open("output.txt", "w")
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n = int(input())
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c = [None for i in range(n+1)]
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for i in range(1, n, 2):
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c[i] = 0
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c[2] = 1
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c[0] = 1
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def recursion(n, c):
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if c[n] != None:
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return c[n]
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kkk = 0
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for i in range(1, n):
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kkk += recursion(i-1, c) * recursion(n-i-1, c)
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c[n] = kkk
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return kkk
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print(recursion(n, c)) |