#include <bits/stdc++.h>

using namespace std;

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

const int DIM = 100000 + 5;

vector < int > a[DIM];

bool f[DIM];

void dfs(int k)
{
    f[k] = true;
    for(auto v : a[k]) {
        if(f[v] == false) {
            dfs(v);
        }
    }
}

int main()
{
    int n, m;

    fin >> n >> m;
    for(int i = 1; i <= m; ++i) {
        int x, y;

        fin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    int sol = 0;
    for(int i = 1; i <= n; ++i) {
        if(f[i] == false) dfs(i), ++sol;
    }
    fout << sol;
    return 0;
}