func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 1e6, maxm = 1e6;   unsigned int degree[maxn + 10], blk[maxn + 10];   namespace find {   unsigned int fa[maxn + 10], siz[maxn + 10];   inline void Init(const unsigned int n) {     iota(fa, fa + n + 1, 0);     fill(siz, siz + n + 1, 1);   }   unsigned int GetFather(const unsigned int x) {     return fa[x] == x ? x : fa[x] = GetFather(fa[x]);   }   inline void Merge(const unsigned int x, const unsigned int y) {     unsigned int fx = GetFather(x), fy = GetFather(y);     if (fx == fy) return;     if (siz[fx] < siz[fy]) swap(fx, fy);     fa[fy] = fx;     siz[fx] += siz[fy];   }   }  // namespace find   int main() {     ios_base::sync_with_stdio(false);     unsigned int n, m;     cin >> n >> m;     find::Init(n);     for (unsigned int i = 0; i < m; ++i) {       unsigned int a, b;       cin >> a >> b;       find::Merge(a, b);       ++degree[a];       ++degree[b];     }     unsigned long long ans = 0;     const unsigned int r = find::GetFather(1);     bool fl = true;     for (unsigned int i = 1; i <= n; ++i) {       if (degree[i] & 0x01) ++blk[find::GetFather(i)];       if (degree[i] && find::GetFather(i) != r) fl = false;     }     if (fl && !blk[r]) {       cout <<  0  << endl;       return 0;     }     for (unsigned int i = 1; i <= n; ++i)       if (find::GetFather(i) == i) {         ans += blk[i] / 2;         if (degree[i] && !blk[i]) ++ans;       }     if (!degree[1] && find::siz[1] == 1 && find::GetFather(1) == 1) ++ans;     cout << ans << endl;     return 0;   }   