#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n, m, i, a, b;
vector<int> v[100005];
int vaz[100005];

void dfs(int nod){
    vaz[nod]=1;

    for(int i=0;i<v[nod].size();i++){
        if(vaz[v[nod][i]]==0){
            dfs(v[nod][i]);
        }
    }
}

int main()
{
    fin>>n>>m;

    for(i=1;i<=m;i++){
        fin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

    int ans=0;
    for(i=1;i<=n;i++){
        if(vaz[i]==0){
            ans++;
            dfs(i);
        }
    }

    fout<<ans;





    return 0;
}