#include<cstdio>
#include<vector>

using namespace std;

int n,m;
vector<int> adj[100010];
bool vis[100010];
int res;

void dfs(int nod)
{
    vis[nod]=1;
    for(vector<int>::iterator it=adj[nod].begin();it!=adj[nod].end();it++)
    {
        if(vis[*it]==0)
        {
            dfs(*it);
        }
    }
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);

    scanf("%d %d",&n,&m);
    int x,y;
    for(int i=1;i<=m;i++)
    {
        scanf("%d %d",&x,&y);
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        if(vis[i]==0)
        {
            res++;
            dfs(i);
        }
    }
    printf("%d",res);
}