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

using namespace std;

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

#define lim 100001

typedef vector<int> VI;
VI v[lim];
int n,m,rez;
int viz[lim];



void dfs(int nod)
{
    viz[nod]=1;

    for(auto it:v[nod])
        if(!viz[it])
            dfs(it);
}



int main()
{
    int i,x,y;

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

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

    return 0;
}