#include <bits/stdtr1c++.h>
using namespace std;

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

int N, M;
int visited[100010];
int cnt, maxi;

void addEdge(vector <int> adj[], int u, int v) {
    adj[u].push_back(v);
    adj[v].push_back(u);
}

int DFS(int u, vector <int> adj[]) {
    visited[u] = 1;
    //cnt++;
    for(int i=0; i<adj[u].size(); i++) {
        if(visited[adj[u][i]] == 0) {
            DFS(adj[u][i], adj);
        }
    }
}

int main()
{
    int x, y, cnt=0;
    fin >> N >> M;
    vector <int> adj[N+1];
    for(int i=0; i < M; i++) {
        fin >> x >> y;
        addEdge(adj, x, y);
    }
    for(int i=1;i <= N; i++) {
        if(!visited[i]){
            cnt++;
            DFS(i, adj);
        }
    }
    cout << cnt;
    return 0;
}