#include <bits/stdc++.h>
using namespace std;

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

const int NMAX = 100001;

vector<int> l[NMAX];
int vis[NMAX];

void dfs(int node) {
    vis[node] = 1;
    for (int vec : l[node]) {
        if (vis[vec] == 0) {
            dfs(vec);
        }
    }
}

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

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

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

    fout << nr;
    return 0;
}