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

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

int n,m,visited[2000001]={0};
vector<vector<int>> l(2000001);

void dfs(int x){
    visited[x] = 1;
    for (const auto &item: l[x]) {
    if(visited[item]==0){
        dfs(item);
    }
    }

}

int main(){
    fin>>n>>m;
    for(int i = 1;i<=m;i++){
        int x,y;
        fin>>x>>y;
        l[x].push_back(y);
        l[y].push_back(x);
    }
    int count = 0;
    for(int i =1; i<=n;i++){
        if(visited[i] == 0){
            count+=1;
            dfs(i);
        }
    }

    fout<<count;


}