#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 10;
const long long mod = 998244353;
const int inf = 0x3f3f3f3f;
const long long INF = 0x3f3f3f3f3f3f3f3f;
const double eps = 1e-7;
long long GCD(long long a, long long b) {
  while (b ^= a ^= b ^= a %= b)
    ;
  return a;
}
long long LCM(long long a, long long b) { return a * b / GCD(a, b); }
long long prime[maxn] = {0}, num_prime = 0;
int isNotPrime[maxn] = {1, 1};
inline long long read() {
  long long X = 0, w = 0;
  char ch = 0;
  while (!isdigit(ch)) {
    w |= ch == '-';
    ch = getchar();
  }
  while (isdigit(ch)) X = (X << 3) + (X << 1) + (ch ^ 48), ch = getchar();
  return w ? -X : X;
}
inline void write(int x) {
  if (x < 0) putchar('-'), x = -x;
  if (x > 9) write(x / 10);
  putchar(x % 10 + '0');
}
void isPrime() {
  for (int i = 2; i < maxn; ++i) {
    if (!isNotPrime[i]) prime[num_prime++] = i;
    for (int j = 0; j < num_prime && i * prime[j] < maxn; ++j) {
      isNotPrime[i * prime[j]] = 1;
      if (!i % prime[j]) break;
    }
  }
  printf("%lld", prime[num_prime - 1]);
}
long long binaryPow(long long a, long long b, long long c) {
  long long ans = 1;
  while (b > 0) {
    if (b & 1) {
      ans = ans * a % c;
    }
    a = a * a % c;
    b >>= 1;
  }
  return ans % c;
}
void BUG() { printf("DEBUG\n"); }
long long n, m;
long long f[maxn];
long long vis[maxn];
long long cnt[maxn];
long long vv[maxn];
int find(int x) { return x == f[x] ? f[x] : f[x] = find(f[x]); }
void bset(int x, int y) {
  int fx = find(x), fy = find(y);
  f[fx] = fy;
}
int main() {
  scanf("%lld %lld", &n, &m);
  for (int i = 1; i <= n; ++i) {
    f[i] = i;
    cnt[i] = 0;
    vis[i] = 0;
    vv[i] = 0;
  }
  for (int i = 1; i <= m; ++i) {
    long long u, v;
    scanf("%lld %lld", &u, &v);
    vis[u]++;
    vis[v]++;
    vv[v] = 1;
    vv[u] = 1;
    bset(u, v);
  }
  vis[1] += 2;
  vv[1] = 1;
  for (int i = 1; i <= n; ++i) {
    if (vis[i] % 2 == 1) cnt[find(i)]++;
    f[i] = find(i);
  }
  long long cnt1 = 0;
  long long ans = 0;
  for (int i = 1; i <= n; ++i) {
    if (cnt[i] != 0) {
      ans += (cnt[i] - 2) / 2;
    }
  }
  for (int i = 1; i <= n; ++i) {
    if (f[i] == i && vv[i] == 1) cnt1++;
  }
  if (cnt1 >= 2 || cnt[find(1)] != 0) ans += cnt1;
  printf("%lld\n", ans);
  return 0;
}
