#include <bits/stdc++.h>

using namespace std;

bool viz[100001];
vector<int> v[100001];

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