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#include<iostream>
#include<cstdio>
#include<vector>
#include<cstring>
using namespace std;
long long read()
{
long long x=0,f=1; char c=getchar();
while(!isdigit(c)){if(c=='-') f=-1;c=getchar();}
while(isdigit(c)){x=x*10+c-'0';c=getchar();}
return x*f;
}
const int N=1000+10;
vector <int> e[N],e2[N];
int dfn[N],dfn_to,low[N],mstack[N],top,belong[N],cnt;
bool vis[N],InStack[N];
void Tarjan(int now,int father)
{
vis[now]=InStack[now]=true;
mstack[++top]=now;
dfn[now]=low[now]=++dfn_to;
for(int i=0;i<int(e[now].size());i++)
if(vis[e[now][i]]==false)
{
Tarjan(e[now][i],now);
low[now]=min(low[now],low[e[now][i]]);
}
else if(e[now][i]!=father and InStack[e[now][i]]==true)
low[now]=min(low[now],dfn[e[now][i]]);
if(low[now]==dfn[now])
{
cnt++;
while(mstack[top+1]!=now)
InStack[mstack[top]]=false,
belong[mstack[top--]]=cnt;
}
}
int n,m;
int dfs(int now,int father)
{
vis[now]=true;
int t_ans=0;
for(int i=0;i<int(e2[now].size());i++)
if(e2[now][i]!=father)
t_ans+=dfs(e2[now][i],now);
if(e2[now].size()==1)
t_ans++;
if(e2[now].size()==0)
t_ans+=2;
return t_ans;
}
int main()
{
for(int o=1;;o++)
{
if(scanf("%d%d",&n,&m)==EOF) break;
for(int i=0;i<=n;i++)
e[i].clear(),e2[i].clear();
for(int i=1;i<=n;i++)
e[i].reserve(4),e2[i].reserve(4);
for(int i=1;i<=m;i++)
{
int s=read(),t=read();
e[s].push_back(t);
e[t].push_back(s);
}
memset(vis,0,sizeof vis);
memset(mstack,0,sizeof mstack);
dfn_to=cnt=0;
for(int i=1;i<=n;i++)
if(vis[i]==false)
Tarjan(i,i);
for(int i=1;i<=n;i++)
for(int j=0;j<int(e[i].size());j++)
if(belong[i]!=belong[e[i][j]])
e2[belong[i]].push_back(belong[e[i][j]]);
memset(vis,0,sizeof vis);
if(cnt==1)
printf("0\n");
else
{
int ans=0;
for(int i=1;i<=n;i++)
if(vis[belong[i]]==false)
ans+=dfs(belong[i],belong[i]);
printf("%d\n",ans/2+ans%2);
}
}
return 0;
}
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