#include <bits/stdc++.h>
#define ll long long
#define nxM 200010
#define mxN 100010
using namespace std;

int n, m, ans;
vector<int> edges[nxM];
bool visited[mxN];

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

void dfs(int x) {
    if (visited[x] == false) {
        visited[x] = true;
        for (int i = 0; i < edges[x].size(); ++i) {
            dfs(edges[x][i]);
        }
    }
}

int main() {
    fin.tie(0);
    ios::sync_with_stdio(0);
    fin >> n >> m;
    for (int i = 1; i <= m; ++i) {
        int x, y;
        fin >> x >> y;
        edges[x].push_back(y);
        edges[y].push_back(x);
    }
    for (int i = 1; i <= n; ++i) {
        if (visited[i] == false) {
            dfs(i);
            ++ans;
        }
    }
    fout << ans;
    return 0;
}