#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>

using namespace std;

void dfs(vector<vector<int>>& adj, vector<bool>& isViz, int k)
{
    isViz[k] = true;
    for(auto i : adj[k])
        if(!isViz[i])
            dfs(adj, isViz, i);
}

int main()
{
    ifstream reader ("dfs.in");
    ofstream writer ("dfs.out");
    int n, m, s;
    reader >> n >> m;
    
    vector <bool> isViz(n + 1);
    vector<vector<int>> adj(n + 1);
    
    for(int i = 0; i < m; ++i)
    {
        int x, y;
        reader >> x >> y;
        
        adj[x].emplace_back(y);
        adj[y].emplace_back(x);
    }
    
    int ntcmp = 0;
    
    for(int i = 1; i <= n; ++i)
    {
        if(!isViz[i])
        {
            dfs(adj,isViz,i);
            ntcmp++;
        }
    }
    
    writer << ntcmp;
    
    return 0;
}