#include <bits/stdc++.h>
#define NMAX 100005
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> Q,v[NMAX];
int prez[NMAX];
void DFS(int x)
{
    prez[x]=1;
   for(auto i:v[x])
      if(prez[i]==0) DFS(i);
}
int main()
{
    int x,y,n,m,k=0,i;
    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(prez[i]==0) DFS(i),k++;
    fout<<k<<"\n";
    return 0;
}