#include <bits/stdc++.h> using namespace std; int main() { int n, m; cin >> n >> m; vector<vector<int>> g(2 * n); for (int i = 0; i < m; i++) { int a, b; cin >> a >> b; a--; b--; g[a].push_back(b); g[b].push_back(a); } vector<int> group(2 * n, -1); function<void(int, int)> dfs = [&g, &group, &dfs](int cur, int root) { for (int next : g[cur]) { if (group[next] == -1) { group[next] = root; dfs(next, root); } } }; for (int i = 0; i < 2 * n; i++) { if (group[i] == -1) { group[i] = i; dfs(i, i); } } vector<int> count(2 * n, 0); for (int i = 0; i < 2 * n; i++) { count[group[i]]++; } int n_odds = 0; for (const int &c : count) { if (c & 1) n_odds++; } cout << n_odds / 2 << '\n'; return 0; }