#include <iostream>
#include <fstream>
#include <vector>
#define DM 100005
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, nrcomp, a, b, viz[DM];
vector <int> g[DM];

void dfs(int nod)
{
    viz[nod] = 1;
    for(auto it: g[nod])
        if(!viz[it])
            dfs(it);
}
int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    for(int i = 1; i <= n; i++)
        if(!viz[i])
        {
            dfs(i);
            nrcomp++;
        }
    fout << nrcomp;
    return 0;
}