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

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, nrc;
vector<int> G[NMAX];
bool viz[NMAX]; //viz[i]=1 daca varful i a fost vizitat si 0 in caz contrar
void citire();
void dfs(int x);

int main()
{int i;
    citire();
    for (i=1; i<=n; i++)
        if (!viz[i])
            {nrc++; dfs(i);}
    fout<<nrc<<'\n';
    return 0;
}

void citire()
{int i, j, k, m;
 fin>>n>>m;
 for (k=0; k<m; k++)
     {
      fin>>i>>j;
      G[i].push_back(j);
      G[j].push_back(i);
     }
 /*for (i=1; i<=n; i++)
     sort(G[i].begin(), G[i].end());    */
}

void dfs(int x)
{int i;
 //fout<<x<<' ';
 viz[x]=1;
 //parcurg vecinii varfului x
 for (i=0; i<G[x].size(); i++)
     if (!viz[G[x][i]])
         dfs(G[x][i]);
}