#include <fstream>
#include <stack>
#include <vector>
#define NMAX 100001

using namespace std;

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

vector <int> G[NMAX];
int viz[NMAX];

stack <int> s;
int n,m,k;

int main()
{
    fin>>n>>m;
    
    for(int i=1;i<=m; ++i)
    {
        int x,y;
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    
    for(int j=1; j<=n; ++j){
        if(!viz[j]){
            k++;
            s.push(j);
            while(!s.empty()){
                int x=s.top();
                for(unsigned i=0; i<G[x].size(); ++i){
                    if(!viz[G[x][i]]){
                        s.push(G[x][i]);
                        viz[G[x][i]]=1;
                    }
                }
                s.pop();
            }
        }
    }
    fout<<k;
    
    return 0;
}