#include<bits/stdc++.h>
using namespace std;
int read(){
	int x = 0,f = 0;char ch=getchar();
	while(!isdigit(ch)){if(ch=='0')f=1;ch=getchar();}
	while(isdigit(ch)){x=x*10+ch-'0';ch=getchar();}
	return f?-x:x;
}
const int N = 101010;
struct Edge{int to,nxt,flow,cap;}e[N<<1];
int head[N],cur[N],S,T,n,m,dis[N],cnt = 1;
queue<int> Q;
void add(int x,int y,int cap)
{
	e[++cnt].cap = cap;e[cnt].flow = 0;e[cnt].nxt = head[x];e[cnt].to = y;head[x] = cnt;
	e[++cnt].cap = 0;  e[cnt].flow = 0;e[cnt].nxt = head[y];e[cnt].to = x;head[y] = cnt;
}
bool Bfs(int s,int t)
{
	while(Q.size()) Q.pop();
	memset(dis,0,sizeof(dis));
	dis[s] = 1;Q.push(s);
	while(Q.size())
	{
		int x = Q.front();Q.pop();
		for(int i = head[x];i;i = e[i].nxt)
		{
			int y = e[i].to;
			if(!dis[y] && e[i].cap > e[i].flow)
			{
				dis[y] = dis[x] + 1;
				Q.push(y);
				if(dis[t]){
					return true;
				}
			}
		}
	}
	return false;
}
int Dfs(int x,int a,int t)
{
	if(x == t || a == 0) return a;
	int flow = 0,f = 0;
	for(int i = cur[x];i;i = e[i].nxt)
	{
		int y = e[i].to;
		if(dis[y] == dis[x] + 1 && ((f = (Dfs(y,min(a,e[i].cap - e[i].flow),t))) > 0))
		{
			a -= f;
			flow += f;
			e[i].flow += f;
			e[i^1].flow -= f;
			if(a == 0) break;
			cur[x] = e[i].nxt;
		}
	}
	return flow;
}
int Ans = 0,col[N];
vector<int> G[N];
void dfs(int x,int Col)
{
	col[x] = Col;
	for(int i = 0;i < G[x].size();i++)
	{
		if(!col[G[x][i]]) dfs(G[x][i],3 - col[x]);
	}
}
signed main()
{
	n = read();m = read();
	Ans = n;S = 0;T = n+1;
	for(int i = 1;i <= m;i++)
	{
		int a = read()+1,b = read()+1;
		G[a].push_back(b);G[b].push_back(a);
		add(a,b,1);
		add(b,a,1);
	}
	for(int i = 1;i <= n;i++) {
		if(!col[i]) dfs(i,1);
	}
	for(int i = 1;i <= n;i++)
	{
		if(col[i] == 1) add(S,i,1);
		if(col[i] == 2) add(i,T,1);
	}
	int maxflow = 0;
	while(Bfs(S,T))
	{
		for(int i = 0;i <= n+1;i++) cur[i] = head[i];
		maxflow += Dfs(S,0x3f3f3f3f,T);
	}
	cout<<Ans-maxflow<<endl;
	return 0;
}