#include <bits/stdc++.h>

using namespace std;

vector <int> v[100005];

int n,m,a,b,nr,viz[100005];

void dfs(int nod){
    viz[nod]=1;
    for (int i=0; i<v[nod].size(); i++){
        if(!viz[v[nod][i]]) dfs(v[nod][i]);
    }
}
int main(){
    ifstream cin("dfs.in");
    ofstream cout("dfs.out");
    cin>>n>>m;
    for (int i=1; i<=m; i++){
        cin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for (int i=1; i<=n; i++){
        if(!viz[i]) dfs(i),nr++;
    }

    cout<<nr;
    return 0;
}