#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout("dfs.out");
vector <int> A[100005];
int BR[100005];
void DFS(int x)
    {
        int i;
        BR[x]=1;
        for(i=0;i<A[x].size();i++)
            if(BR[A[x][i]]==0)
            DFS(A[x][i]);
    }
int main()
{
    int n,m,i,x,y,rez=0;
    fin>>n>>m;
    for(i=1;i<=m;i++)
        {
            fin>>x>>y;
            A[x].push_back(y);
            A[y].push_back(x);
        }
    for(i=1;i<=n;i++)
        if(BR[i]==0)
        {
            DFS(i);
            rez++;
        }
    fout<<rez<<'\n';
    fin.close();
    fout.close();
    return 0;
}