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

bool vf[200005];
vector<int> graf[300005];

bool dfs(int nod){
    vf[nod] = 1;
    for(int i = 0;i<graf[nod].size();i++){
        if(vf[graf[nod][i]] == 0){
            dfs(graf[nod][i]);
        }
    }
}

int main(void){
    ofstream cout("dfs.out");
    ifstream cin("dfs.in");
    int n, m;
    cin >> n >> m;
    for(int i = 1;i<=m;i++){
        int a, b;
        cin>> a >> b;
        graf[a].push_back(b);
        graf[b].push_back(a);
    }
    int cnt = 0;
    for(int i = 1;i<=n;i++){
        if(vf[i] == 0){
            cnt++;
            dfs(i);
        }
    }
    cout << cnt;
}