#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,a[100005];
vector <int> G[100005];
void citire()
{
    fin>>n>>m;
    int x,y;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}
void dfs(int x)
{
    a[x]=1;
    for(auto &v: G[x])
    {
        if(!a[v])
            dfs(v);
    }
}
int main()
{
    citire();
    int nr=0;
    for(int i=1; i<=n; i++)
    {
        if(!a[i])
        {
            dfs(i);
            nr++;
        }
    }
    fout<<nr;
    return 0;
}