#include<bits/stdc++.h>
#define Nmax 200001
int viz[Nmax],n,m,a,b,counter;
using namespace std;
vector <int> adj[Nmax];
void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0;i<adj[nod].size();i++)
    {
        if(!viz[adj[nod][i]])
            dfs(adj[nod][i]);
    }
}
int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin>>n>>m;
    for(int i=0;i<=m;i++)
    {
        fin>>a>>b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for(int i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            counter++;
        }
    }
    fout<<counter;
}