#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); ++i)

#include <atcoder/dsu>

int main() {
  int n, m;
  cin >> n >> m;
  atcoder::dsu d(2 * n);
  rep(_, m) {
    int a, b;
    cin >> a >> b;
    --a, --b;
    d.merge(a, b);
  }
  auto g = d.groups();
  ll ans = 0;
  for (auto&& e : g) ans += e.size() % 2;
  cout << (ans + 1) / 2 << endl;
  return 0;
}