#include <bits/stdc++.h>

#define pb push_back
#define x first
#define y second
#define mp make_pair

using namespace std;

int use[100006], a, b;

vector<int> v[100006];

void dfs(int k)
{
    use[k]=1;
    for(int i=0; i<v[k].size(); i++)
    {
        if(!use[v[k][i]])
                dfs(v[k][i]);
    }
}
int n, m;
int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    cin>>n>>m;

    for(int i=1; i<=m; i++)
    {
        cin>>a>>b;

        v[a].pb(b);
        v[b].pb(a);
    }
    int ans=0;
    for(int i=1; i<=n; i++)
    {
        if(!use[i])
            dfs(i), ans++;
    }
    cout<<ans<<'\n';
    return 0;
}