#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <fstream>
#include <iterator>
#include <random>
#include <assert.h>
using namespace std;

const string file = "dfs";

const string infile = file + ".in";
const string outfile = file + ".out";

const int INF = 0x3f3f3f3f; 

//#define ONLINE_JUDGE

void dfs(int x, vector<vector<int> >& G, vector<bool>& viz)
{
    viz[x] = true;
    stack<int> st;
    st.push(x);
    while(st.empty() == false)
    {
        x = st.top();
        st.pop();
        for(vector<int>::iterator itr = G[x].begin();
                itr != G[x].end();
                itr++)
        {
            if(viz[*itr] == false)
            {
                viz[*itr] = true;
                st.push(*itr);
            }
        }
    }
}

int main()
{
#ifdef ONLINE_JUDGE
	ostream &fout = cout;
	istream &fin = cin;
#else
	fstream fin(infile.c_str(), ios::in);
	fstream fout(outfile.c_str(), ios::out);
#endif	

    int N, M;
    fin >> N >> M;
    vector<vector<int> > G(N + 1);
    vector<bool> viz(N + 1, false);
    for(int i = 0; i < M; i++)
    {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    int Sol = 0;
    for(int i = 1; i <= N; i++)
    {
        if(viz[i] == false)
        {
            Sol++;
            dfs(i, G, viz);
        }
    }
    fout << Sol << "\n";
#ifdef ONLINE_JUDGE
#else
    fout.close();
	fin.close();
#endif
}