#include <bits/stdc++.h>
using namespace std;

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

vector<int> L[1000001];
int vis[1000001];

void dfs(int node){
    vis[node] = 1;
    for(auto vec : L[node]){
        if(vis[vec] == 0){
            dfs(vec);
        }
    }
}

int main(){
    int n, m;
    fin >> n >> m;

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

    int nr = 0;
    for(int i = 1; i <= n; i++){
        if(vis[i] == 0){
            dfs(i);
            nr++;
        }
    }

    fout << nr << "\n";
    return 0;
}