#include<bits/stdc++.h>

using namespace std;

const int NMAX = 1e5 + 5;
vector<int> v[NMAX];
bool viz[NMAX];
int n, m, ans;

void dfs(int node)
{
    viz[node] = 1;
    for(auto u : v[node])
    {
        if(!viz[u])
            dfs(u);
    }
}

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

    cin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int a, b;
        cin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

    for(int i = 1; i <= n; i++)
    {
        if(!viz[i])
        {
            dfs(i);
            ans++;
        }
    }

    cout << ans;
}