#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int i,n,m,nr,viz[200001],x,y;
vector <int>G[200001];
void dfs(int nod){
    viz[nod]=1;
    for(int j=0;j<G[nod].size();j++)
        if(viz[G[nod][j]]==0)
        dfs(G[nod][j]);
    }

int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++){
        f>>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);
    }
    g<<nr;
    return 0;
}