#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

vector<int> G[100003];
bool viz[100003];
int n, m, k, a, b;

void DFS(int v){
    viz[v] = 1;
    for(int i = 0; i < G[v].size(); i++){
        if(!viz[G[v][i]]){
            DFS(G[v][i]);
        }
    }
}

int main(){
    fin >> n >> m;
    for(int i = 1; i <= m; i++){
        fin >> a >> b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    for(int i = 1; i <= n; i++){
        if(!viz[i]){
            DFS(i);
            k++;
        }
    }
    fout << k;
    return 0;
}