#include <iostream>
#include <algorithm>
#include <fstream>
#include <stack>
#include <vector>

using namespace std;

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

const int NMAX = 100002;

vector<int> Graf[NMAX];

int sol = 0;
int viz[NMAX];
int n,m;

void dfs(int start)
{
    viz[start]=1;
    int l = Graf[start].size();
    for(int i=0;i<l;i++)
    {
        if(viz[Graf[start][i]]==0)
        {
            dfs(Graf[start][i]);
        }
    }
}

void solve()
{
    for(int i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            sol++;
        }
    }
}


void citire()
{
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        in>>x>>y;
        Graf[x].push_back(y);
        Graf[y].push_back(x);
    }
}

void afisare()
{
    out<<sol;
}


int main()
{
    citire();
    solve();
    afisare();
}