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 1 #include<cstdio>
 2 #include<cstring>
 3 #include<algorithm>
 4 #include<vector>
 5 using namespace std;
 6 const int N=1010;
 7 vector<int>g[N];
 8 int f[N];
 9 int n,m;
10 int mark[N];
11 
12 int Find(int x)
13 {
14     return (x==f[x])?x:(f[x]=Find(f[x]));
15 }
16 
17 int main()
18 {
19   //  freopen("1.in","r",stdin);
20   //  freopen("1.out","w",stdout);
21     while (~scanf("%d%d",&n,&m)) {
22         for (int i=0;i<n;i++) {
23             f[i]=i;
24             g[i].clear();
25         }
26         while (m--) {
27             int x,y;
28             scanf("%d%d",&x,&y);
29             g[x].push_back(y);
30             g[y].push_back(x);
31             int xx=Find(x),yy=Find(y);
32             if (xx!=yy) f[xx]=yy;
33         }
34         memset(mark,0,sizeof(mark));
35         int ans=0;
36         for (int i=0;i<n;i++) {
37             int k=Find(i);
38             mark[k]++;
39         }
40         int cnt=0;
41         for (int i=0;i<n;i++) {
42             if (mark[i]>1) cnt++;
43         }
44         if (cnt==1) {
45             ans=0;
46             for (int i=0;i<n;i++) {
47                 if (g[i].size()&1) ans++;
48             }
49             printf("%d
",ans/2);
50             continue;
51         }
52         for (int i=0;i<n;i++) {
53             if (mark[i]>1) {
54                 ans++;
55                 int tmp=0;
56                 for (int j=0;j<n;j++) {
57                     if (Find(j)==i&&(g[j].size()&1)) {
58                         tmp++;
59                     }
60                 }
61                 if (tmp>2) ans+=(tmp-2)/2;
62             }
63         }
64         printf("%d
",ans);
65     }
66     return 0;
67 }