#include <bits/stdc++.h>

using namespace std;

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

int n, m, cnt;
vector<int> G[100005];
bitset<100005> v;

void dfs(int nod) {
    v[nod] = true;
    for(auto i : G[nod]) {
        if(!v[i]) {
            dfs(i);
        }
    }
}

int main() {
    fin >> n >> m;
    for(int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    fin.close();
    for(int i = 1; i <= n; i++) {
        if(!v[i]) {
            cnt++;
            dfs(i);
        }
    }
    fout << cnt;
    return 0;
}