#include <fstream>
#include <vector>
#define NMAX 100002

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, nr;
vector<int>G[NMAX]; //G[i] lista de adiacenta a vf i
bool viz[NMAX];

void citire();
void dfs(int x);

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

void dfs(int x)
{
int i;
viz[x]=1;
for (i=0; i<G[x].size(); i++)
    if (viz[G[x][i]]==0)
       dfs(G[x][i]);
}