#include <bits/stdc++.h>
using namespace std;
template <class Ta, class Tb>
inline Tb cast(Ta a) {
  stringstream ss;
  ss << a;
  Tb b;
  ss >> b;
  return b;
};
const double EPS = 1e-9;
const int INF = 1000000000;
const int MOD = 1000000007;
const int diri[8] = {-1, 0, 1, 0, -1, 1, 1, -1};
const int dirj[8] = {0, 1, 0, -1, 1, 1, -1, -1};
vector<int> tree;
int root(int n) {
  if (tree[n] == -1) return n;
  return tree[n] = root(tree[n]);
}
int main() {
  int n, m;
  cin >> n >> m;
  vector<int> deg(n, 0);
  tree = vector<int>(n, -1);
  for (int i = 0; i < m; ++i) {
    int x, y;
    cin >> x >> y;
    --x;
    --y;
    ++deg[x];
    ++deg[y];
    int a = root(x), b = root(y);
    if (a != b) {
      tree[b] = a;
    }
  }
  int c = 0;
  for (int i = 0; i < n; ++i)
    if (deg[i] != 0 and tree[i] == -1) ++c;
  if (deg[0] == 0 and c > 0) ++c;
  int s = 0;
  for (int i = 0; i < n; ++i)
    if (deg[i] % 2 == 1) ++s;
  if (c == 1)
    cout << s / 2 << endl;
  else {
    vector<int> v(n, 0);
    for (int i = 0; i < n; ++i)
      if (deg[i] % 2 == 1) v[root(i)] = 1;
    int t = 0;
    for (int i = 0; i < n; ++i) t += v[i];
    cout << c + s / 2 - t << endl;
  }
}
