#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,x,y,i,compconx;
bool viz[100001];


vector <int> v[1000001];
void dfs(int node){

    viz[node]=1;
    vector <int>::iterator it;
    for(it=v[node].begin();it<=v[node].end();it++)
        if(viz[*it]==0)
                dfs(*it);


}




int main()
{
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0){
            ++compconx;
            dfs(i);

        }
    }
    fout<<compconx;
    return 0;
}