#include <bits/stdc++.h>

using namespace std;

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

vector <int> mv[200005];
int viz[100005];
queue <int> q;
int n,m;

void BFS(int x){
    int i;

    q.push(x);
    viz[x]=1;

    while(!q.empty()){
        x=q.front();
        q.pop();

        for(i=0;i<mv[x].size();i++)
            if(!viz[mv[x][i]]){
                viz[mv[x][i]]=1;
                q.push(mv[x][i]);
            }
    }
}

int main(){
    int i,j,x,y,ans=0;

    fin>>n>>m;

    for(i=1;i<=m;i++){
        fin>>x>>y;
        mv[x].push_back(y);
        mv[y].push_back(x);
    }

    for(i=1;i<=n;i++){
        if(!viz[i]){
            ans++;
            BFS(i);
        }
    }

    fout<<ans;

    return 0;
}