#include<bits/stdc++.h>
#define ll long long
#define db double
#define ull unsigned long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define FR first
#define SE second
using namespace std;
inline int read() {
  int x = 0; bool op = false;
  char c = getchar();
  while(!isdigit(c))op |= (c == '-'), c = getchar();
  while(isdigit(c))x = (x << 1) + (x << 3) + (c ^ 48), c = getchar();
  return op ? -x : x;
}
const int N = 1e5 + 10;
int n, m;
int vis[N], f[N], sz[N];
vector<int> G[N];
int find(int x) {return f[x] == x ? x : f[x] = find(f[x]);}
void unionn(int x, int y) {
  x = find(x); y = find(y);
  if(x == y)return ;
  f[y] = x; sz[x] += sz[y];
  return ;
}
int main() {
  n = read(); m = read();
  for(int i = 1; i <= n; i++)f[i] = i, sz[i] = 1;
  for(int i = 1; i <= m; i++) {
    int u = read(), v = read();
    G[u].pb(v); G[v].pb(u);
    unionn(u, v);
  }
  int co = 0, ce = 0;
  for(int i = 1; i <= n; i++)if(find(i) == i)
    ((sz[i] & 1) ? co : ce) ^= 1;
  if(!co && !ce)return puts("0"), 0;
  int ans = 0;
  for(int i = 1; i <= n; i++) {
    if(find(i) != i)continue;
    vis[i] = true;
    if(co && ce)ans += (~sz[i] & 1) * sz[i];
    else if(co)ans += (sz[i] & 1) * (2 * sz[i] - 1);
    else ans += (~sz[i] & 1) * (sz[i] - 1);
  }
  printf("%d\n", ans);
  return 0;
}