#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

#define lim 100010
int n,m,rez;
vector <int> G[lim];
bool viz[lim];


void dfs(int i)
{
    viz[i]=true;
    for(auto it:G[i])
        if(!viz[it])
            dfs(it);
}


int main()
{
    int x,y;
    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    rez=0;
    for(int i=1; i<=n; i++)
        if(!viz[i])
            dfs(i), rez++;

    fout<<rez;

    fin.close();
    fout.close();
    return 0;
}