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

using namespace std;

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

vector <int> n[100005];
int viz[100005];

void dfs(int nod)
{
    for(auto i : n[nod])
    {
        if(!viz[i])
        {
            viz[i]=1;
            dfs(i);
        }
    }
}
int main()
{
    int N,M,i,x,y;
    f>>N>>M;
    for(i=1; i<=M; i++)
    {
        f>>x>>y;
        n[x].push_back(y);
        n[y].push_back(x);
    }
    int nr=0;
    for(i=1; i<=N; i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            nr++;
        }
    }
    g<<nr;
    return 0;
}