#include<iostream>
#include<vector>
#include<fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, x, y, i;
int comp = 0;
vector<vector<int>> ad;
vector<int> vi;

void dfs(int nod)
{
    vi[nod] = 1;
    for(int i:ad[nod])
        if(!vi[i])
            dfs(i);
}
int main()
{
    fin>>n>>m;
    ad.resize(n+1);
    vi.resize(n+1,0);
    for(i=1;i<=m;i++){
        fin>>x>>y;
        ad[x].push_back(y);
        ad[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(!vi[i]){
            comp++;
            dfs(i);
        }
    fout<<comp;
    fin.close();
    fout.close();
    return 0;
}