#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

vector<int> l[200001];
bool viz[100001];

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

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

int n,m,i,x,y,nr;

int main()
{
    fin >> n >> m;
    for(int i=1;i<=m;i++){
        fin >> x >> y;
        l[x].push_back(y);
        l[y].push_back(x);}
 for(int i=1;i<=n;i++)
        if(viz[i]==0)
            {dfs(i); nr++;}
        fout << nr;
    return 0;
}