#include <fstream>
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,a,b,viz[100005],cnt,x;
vector <int> v[100005];
queue <int> q;
int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(int i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            cnt++;
            viz[i]=1;
            q.push(i);
            while(!q.empty())
            {
                x=q.front();
                for(int j=0;j<v[x].size();j++)
                {
                    if(viz[v[x].at(j)]==0)
                    {
                        q.push(v[x].at(j));
                        viz[v[x].at(j)]=1;
                    }
                }
                q.pop();
            }
        }
    }
    fout<<cnt;
    fin.close();
    fout.close();
    return 0;
}