27 lines
591 B
Python
27 lines
591 B
Python
from __future__ import print_function
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import sys
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N = int(sys.stdin.readline())
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K = int(sys.stdin.readline())
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D = {}; done = 0
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for line in sys.stdin:
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C1, C2, P1, P2 = line.split(); C1, C2 = map(int, (C1, C2))
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if P1 == P2: done += 1
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D.setdefault(P1, set()).add(C1)
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D.setdefault(P2, set()).add(C2)
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doubles = len([ k for k, v in D.iteritems() if len(v) == 2 ])
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singles = len([ k for k, v in D.iteritems() if len(v) == 1 ])
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left = N - 2*doubles - singles
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answer = doubles - done
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if singles == 0 and left == 2:
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answer += 1
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elif singles == left:
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answer += left
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print(answer)
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