#include <iostream>
#include<fstream>
#include <vector>
#define maxi 100010
using namespace std;

vector<int>L[maxi];
int N,M,viz[maxi];

void dfs(int nod)
{
    viz[nod]=1;
    for(auto i: L[nod])
        if(viz[i]==0)
            dfs(i);
}

int main()
{
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    int x,y;
    f>>N>>M;
    for(int i=1;i<=M;i++)
    {
        f>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    int nr=0;
    for(int i=1;i<=N;i++)
        if(viz[i]==0)
        {
            dfs(i);
            nr++;
        }
    g<<nr;



    return 0;
}