#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

void DFS(int nod, int v[], vector<int> graf[])
{
    v[nod]=1;
    for(auto it:graf[nod])
    {
        if(v[it]==0)
            DFS(it,v,graf);
    }
}



int main()
{
    int n,m;
    fin>>n>>m;
    vector<int> graf[n+1];
    int v[n+1]={0};
    while(m--)
    {
        int x,y;
        fin>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);

    }
    int nr=0;
    for(int i=1;i<=n;i++)
        if(v[i]==0)
            {
                nr++;
                DFS(i,v,graf);
            }
    fout<<nr;
    return 0;
}