#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int NMAX = 100005;
vector <int> graph[NMAX];
bitset <NMAX> seen;
int n, m;
void dfs(int node)
{
    seen[node] = 1;
    for(auto& x : graph[node])
        if(seen[x] == 0)
            dfs(x);
}
int main()
{
    int i, u, v;
    fin >> n >> m;
    for(i = 1;i <= m;i++)
    {
        fin >> u >> v;
        graph[u].push_back(v);
        graph[v].push_back(u);
    }
    int ans = 0;
    for(i = 1;i <= n;i++)
        if(seen[i] == 0)
        {
            dfs(i);
            ans++;
        }
    fout << ans;
    return 0;
}