import types _atcoder_code = """ # Python port of AtCoder Library. __version__ = '0.0.1' """ atcoder = types.ModuleType('atcoder') exec(_atcoder_code, atcoder.__dict__) _atcoder_dsu_code = """ import typing class DSU: ''' Implement (union by size) + (path halving) Reference: Zvi Galil and Giuseppe F. Italiano, Data structures and algorithms for disjoint set union problems ''' def __init__(self, n: int = 0) -> None: self._n = n self.parent_or_size = [-1] * n def merge(self, a: int, b: int) -> int: assert 0 <= a < self._n assert 0 <= b < self._n x = self.leader(a) y = self.leader(b) if x == y: return x if -self.parent_or_size[x] < -self.parent_or_size[y]: x, y = y, x self.parent_or_size[x] += self.parent_or_size[y] self.parent_or_size[y] = x return x def same(self, a: int, b: int) -> bool: assert 0 <= a < self._n assert 0 <= b < self._n return self.leader(a) == self.leader(b) def leader(self, a: int) -> int: assert 0 <= a < self._n parent = self.parent_or_size[a] while parent >= 0: if self.parent_or_size[parent] < 0: return parent self.parent_or_size[a], a, parent = ( self.parent_or_size[parent], self.parent_or_size[parent], self.parent_or_size[self.parent_or_size[parent]] ) return a def size(self, a: int) -> int: assert 0 <= a < self._n return -self.parent_or_size[self.leader(a)] def groups(self) -> typing.List[typing.List[int]]: leader_buf = [self.leader(i) for i in range(self._n)] result: typing.List[typing.List[int]] = [[] for _ in range(self._n)] for i in range(self._n): result[leader_buf[i]].append(i) return list(filter(lambda r: r, result)) """ atcoder.dsu = types.ModuleType('atcoder.dsu') exec(_atcoder_dsu_code, atcoder.dsu.__dict__) DSU = atcoder.dsu.DSU import sys input = sys.stdin.readline # from atcoder.dsu import DSU def read(): N, M = map(int, input().strip().split()) AB = [] for i in range(M): a, b = map(int, input().strip().split()) AB.append((a, b)) return N, M, AB def solve(N, M, AB): dsu = DSU(2 * N) for a, b in AB: dsu.merge(a-1, b-1) ans = 0 for group in dsu.groups(): ans += len(group) % 2 ans //= 2 return ans if __name__ == "__main__": inputs = read() outputs = solve(*inputs) if outputs is not None: print("%s" % str(outputs))