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

#define Nmax 100000
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");

int n,m,a,b,sol;
bool fr[Nmax+1];
vector <int> con[Nmax+1];
void dfs(int pos){
    fr[pos]=1;
    for (int i=0;i<con[pos].size();i++)
        if (!fr[con[pos][i]])
            dfs(con[pos][i]);
}
int main()
{
    fin>>n>>m;
    for (int i=0;i<m;i++){
        fin>>a>>b;
        con[a].push_back(b);
        con[b].push_back(a);
    }
    for (int i=1;i<=n;i++){
        if (!fr[i]){
            sol++;
            dfs(i);
        }
    }
    fout<<sol;
    return 0;
}