#include <iostream>

#include <fstream>

#include <vector>

using namespace std;

ifstream fin("dfs.in");

ofstream fout("dfs.out");

vector<vector<int>>g;

vector<bool>viz;

int n,m;

void read()

{

int x,y;

fin>>n>>m;

g=vector<vector<int>>(n+1);

viz=vector<bool>(n+1);

for(int i=1; i<=m; i++)

{

fin>>x>>y;

g[x].push_back(y);

g[y].push_back(x);

}

}

void DFS(int np)

{

viz[np]=1;

for(auto e:g[np])

if(!viz[e])

DFS(e);

}

int main()

{

int nrc=0;

read();

for(int i=1; i<=n; i++)

{

if(!viz[i])

{

nrc++;

DFS(i);

}

}

fout<<nrc;

}