#include <bits/stdc++.h>

using namespace std;

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

int n, m;
vector<vector<int>> v(100001);
int comp[100001];

void dfs(int x, int val) {
    comp[x] = val;
    for(auto i : v[x]) {
        if(comp[i] == 0) {
            dfs(i, val);
        }
    }
}

int main() {
    fin >> n >> m;
    for(int i = 1; i <= m; i++) {
        int a, b;
        fin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    int cnt = 0;
    for(int i = 1; i <= n; i++) {
        if(comp[i] == 0) {
            dfs(i, ++cnt);
        }
    }
    fout << cnt;
    return 0;
}