#include <bits/stdc++.h>
#define ll long long
using namespace std;

ifstream f ( "dfs.in" );
ofstream g ( "dfs.out");

vector < int > v[100005];
bool viz[100005];
int n,m;

void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0;i<v[nod].size();i++)
        if(!viz[v[nod][i]]) dfs(v[nod][i]);
}

main()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int a,b;
        f>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    int ans=0;
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {   ans++;
            dfs(i);
        }
    g<<ans;
    return 0;
}