#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

vector<vector<int>> G;
vector<int> viz;

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

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

    G = vector<vector<int>>(n + 1);
    viz = vector<int>(n + 1);

    for(int i = 0; i < m; i ++){
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    int cnt = 0;
    for(int i = 1; i <= n; i ++)
        if(!viz[i]){
            dfs(i);
            cnt ++;
        }
    
    fout << cnt << "\n";

    return 0;
}