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

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