#include <iostream>
#include <vector>

using namespace std;
/**
  muchii: 1 2 ; 2 6 ; 2 4; 4 7 ; 7 3 ; 3 8 ; 8 5 ; 7 1
**/

const int nmax=1e5 + 2;
vector<int> adj[nmax];
bool viz[nmax];

void dfs(int nod)
{
    viz[nod]=1;
    for(auto& to : adj[nmax])  ///int i=0;i<adj[nod].size();++i
    {
        /// to=adj[nod][i];
        if(!viz[to])
            dfs(to);
    }
}

int main()
{
    int n, m, i;
    cin>>n>>m;
    for(i=1;i<=m;++i)
    {
        int x, y;
        cin>>x>>y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    int ct=0;
    for(int nod=1;nod<=n;++nod)
    {
        if(!viz[nod])
        {
            dfs[nod];
            ct++;
        }
    }
    cout<<ct<<'\n';
    return 0;
}