#include <iostream>
#include<fstream>
#include<vector>
using namespace std;ifstream fin("dfs.in");ofstream fout("dfs.out");
vector<int>v[100001];
int n,m,a,b,rsp,i;bool viz[100001];
void dfs(int idx){
    viz[idx]=1;
    for(int j=0;j<v[idx].size();j++){
        int id1=v[idx][j];
        if(viz[id1])continue;
        dfs(id1);
    }
}
int main()
{
    fin>>n>>m;for(i=1;i<=m;i++){
    fin>>a>>b;
    v[a].push_back(b);
    v[b].push_back(a);
    }
    for(i=1;i<=n;i++){
        if(viz[i])continue;
        rsp++;
        dfs(i);
    }fout<<rsp;
    return 0;
}