#include <fstream>
#include <cstring>
#include <vector>
#include <algorithm>
#include <queue>

using namespace std;

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

const int NMAX = 1e5;

int n, m, i, cnt, f[2 * NMAX + 5], a, b;
vector<int> v[NMAX + 5];

void dfs(int node){
    f[node] = 1;
    for(auto i: v[node]){
        if(!f[i])
            dfs(i);
    }
}

void solve(){
    in >> n >> m;
    for(i = 1; i <= m; ++i){
        in >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(i = 1; i <= n; ++i){
        if(!f[i]){
            dfs(i);
            cnt++;
        }
    }
    out << cnt;
}

int main()
{
    solve();
    return 0;
}