#include <bits/stdc++.h> #include <atcoder/all> using namespace std; using namespace atcoder; using ll = long long; using P = pair<ll,ll>; #define rep(i,n) for(int (i)=0;(i)<(n);(i)++) #define rep2(i,m,n) for(int (i)=(m);(i)<(n);(i)++) #define rep2ll(i,m,n) for(ll (i)=(m);(i)<(n);(i)++) #define ALL(obj) (obj).begin(), (obj).end() #define rALL(obj) (obj).rbegin(), (obj).rend() const ll INF60 = 1LL<<60;//1152921504606846976 const int INF30 = 1<<30; using mint = modint998244353; using VL = vector<ll>; using VVL = vector<VL>; using VVVL = vector<VVL>; using VM = vector<mint>; using VVM = vector<VM>; using VVVM = vector<VVM>; using VD = vector<double>; using VVD = vector<VD>; using VVVD = vector<VVD>; template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; } template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; } int main(){ ios::sync_with_stdio(false); cin.tie(0); ll n, m; cin>>n>>m; VL u(m), v(m); rep(i,m) cin>>u[i]>>v[i], u[i]--, v[i]--; VL din(n, 0), dout(n, 0); atcoder::dsu uf(n); rep(i,m){ uf.merge(u[i], v[i]); din[v[i]]++; dout[u[i]]++; } ll ans = 0; ll sz = 0; for(auto g:uf.groups()){ ll dsum = 0; for(auto x:g) dsum += abs(din[x] - dout[x]); ans += max(0LL, dsum/2-1); sz += max(din[g[0]],dout[g[0]])!=0; } cout<<ans+max(0LL,sz-1); return 0; }