import java.util.*; import java.io.*; @SuppressWarnings("unused") public class Main { private static class DisjointSet { public int[] upper; // minus:num_element(root) plus:root(normal) // public int[] w; public DisjointSet(int n) { upper = new int[n]; Arrays.fill(upper, -1); // w = new int[n]; } public DisjointSet(DisjointSet ds) { this.upper = Arrays.copyOf(ds.upper, ds.upper.length); } public int root(int x) { return upper[x] < 0 ? x : (upper[x] = root(upper[x])); } public boolean equiv(int x, int y) { return root(x) == root(y); } public boolean union(int x, int y) { x = root(x); y = root(y); if(x != y) { if(upper[y] < upper[x]) { int d = x; x = y; y = d; } // w[x] += w[y]; upper[x] += upper[y]; upper[y] = x; } return x == y; } public int count() { int ct = 0; for(int u : upper){ if(u < 0)ct++; } return ct; } public int[][] toBucket() { int n = upper.length; int[][] ret = new int[n][]; int[] rp = new int[n]; for(int i = 0;i < n;i++){ if(upper[i] < 0)ret[i] = new int[-upper[i]]; } for(int i = 0;i < n;i++){ int r = root(i); ret[r][rp[r]++] = i; } return ret; } } private static void solve() { int n = ni(); int m = ni(); var ds = new DisjointSet(n * 2); for (int i = 0; i < m; i ++) { ds.union(ni()-1, ni()-1); } int ret = 0; for (int i = 0; i < n * 2; i ++) { if (i == ds.root(i)) { ret += -ds.upper[i] / 2; } } ret = n - ret * 2; System.out.println(ret); } public static void main(String[] args) { new Thread(null, new Runnable() { @Override public void run() { solve(); out.flush(); } }, "", 64000000).start(); } private static PrintWriter out = new PrintWriter(System.out); private static StringTokenizer tokenizer = null; private static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 32768); public static String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new java.util.StringTokenizer(reader.readLine()); } catch (Exception e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } private static double nd() { return Double.parseDouble(next()); } private static long nl() { return Long.parseLong(next()); } private static int[] na(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = ni(); return a; } private static char[] ns() { return next().toCharArray(); } private static long[] nal(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nl(); return a; } private static int[][] ntable(int n, int m) { int[][] table = new int[n][m]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[i][j] = ni(); } } return table; } private static int[][] nlist(int n, int m) { int[][] table = new int[m][n]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[j][i] = ni(); } } return table; } private static int ni() { return Integer.parseInt(next()); } }