// problema
// solutie de

#include <iostream>
#include <fstream>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <deque>

using namespace std;

#define NMax 100000

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

int n, m, v[NMax + 3];
vector<int> leg[NMax + 3];

void input() {
    fin >> n >> m;
    int x, y;
    for (int i = 1; i <= m; ++i) {
        fin >> x >> y;
        leg[x].push_back(y);
        leg[y].push_back(x);
    }
}

void dfs(int nod) {
    v[nod] = 1;
    for (auto vec : leg[nod]) if (!v[vec]) dfs(vec);
}

void solve() {
    int c = 0;
    for (int i = 1; i <= n; ++i) if (!v[i]) {
        ++c;
        dfs(i);
    }
    fout << c;
}

int main() {
    input();
    solve();
}