#include <bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

int viz[100005],n,m,i,nr,x,y;
vector <int> G[100005];

void dfs(int nod)
{
    viz[nod]=1;
    for(auto &it : G[nod])
    {
        if(viz[it]==0)
        {
            dfs(it);
        }
    }
}

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]==0)
        {
            nr++;
            dfs(i);
        }
    }
    fout<<nr;
    fin.close();
    fout.close();
    return 0;
}