#include <bits/stdc++.h>

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

const int NMAX = 1e5 + 5;

vector<int> G[NMAX];
int n, m;
bool checked[NMAX];

void dfs(int nod){
    checked[nod] = true;
    for(auto i : G[nod]){
        if(!checked[i]){
            dfs(i);
        }
    }
}

int main(){
    f >> n >> m;
    for(int i = 1; i <= m; ++i){
        int x, y;
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    int cnt = 0;
    for(int i = 1; i <= n; ++i){
        if(!checked[i]){
            dfs(i);
            cnt++;
        }
    }
    g << cnt;
    return 0;
}