#include <fstream>
#include <vector>
#include <deque>

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

int n,m,i,x,y,viz[100005],nr;
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]]==0)
            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]==0){
            nr++;
            dfs(i);
        }
    }
    fout<<nr;
    return 0;
}