#include <fstream>
#include <iostream>
#include <string>
#include <queue>
#include <vector>
#include <string.h>
#include <iomanip>
using namespace std;
const string file = "dfs";
const string infile = file + ".in";
const string outfile = file + ".out";
#define MAXN 100001
int N;
int M;
int NrConex;
bool viz[MAXN];
vector<int> G[MAXN];
void citire()
{
fstream fin(infile.c_str(), ios::in);
fin >> N;
fin >> M;
for(int i = 0; i < M; i++)
{
int x, y;
fin >> x >> y;
G[x - 1].push_back(y - 1);
G[y - 1].push_back(x - 1);
}
fin.close();
}
void dfs(int x)
{
if(viz[x] == true)
return;
viz[x] = true;
for(vector<int>::iterator itr = G[x].begin(); itr != G[x].end(); itr++)
{
dfs(*itr);
}
}
void solve()
{
for(int i = 0; i < N; i++)
{
if(viz[i] == false)
{
NrConex ++;
dfs(i);
}
}
}
void afisare()
{
fstream fout(outfile.c_str(), ios::out);
fout << NrConex << "\n";
fout.close();
}
int main()
{
citire();
solve();
afisare();
}