#include<bits/stdc++.h>

using namespace std;

int visited[1000004];
vector<int> graph[1000003];

void dfs(int nod){

    visited[nod] = 1;
    for(auto it:graph[nod]){
        if(visited[it] == 0)
            dfs(it);
    }


}

int main(){
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n , m ;
    in >> n >> m ;
    int x , y ;
    for(int i = 0 ; i < m ; i++){
        in >> x >> y ;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    int ans = 0 ;
    for(int i = 1 ; i <= n ; i++ ){
        if(visited[i] == 0 ){
            dfs(i);
            ans ++;
        }
    }
    out << ans ;
    return 0 ;

}