#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
#include <stack>
using namespace std;

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





int main(){
    
    int n,m;
    fin>>n>>m;
    vector<vector<int>> adj(n+1);
    vector<bool> visited(n+1,false);
    for(int i=0;i<m;i++){
        int x,y;
        fin>>x>>y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    stack<int> s;
    int component = 0;
    for(int i=1;i<=n;i++){
        if(!visited[i])
        {
            s.push(i);
            visited[i] = true;
            component++;
            while(!s.empty())
            {
                int n = s.top();
                s.pop();

                for(auto it: adj[n]){
                    if(!visited[it]){
                        visited[it] = true;
                        s.push(it);
                    }
                }
            }
        }
    }
    fout<<component;

    
    return 0;
}