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

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n, m, nrc;
vector<int> G[NMAX];
bool uz[NMAX];
void citire();
void dfs(int x);
int main()
{ int i;
    citire();
    for (i=1; i<=n; i++)
        if (uz[i]==0)
        {
            uz[i]=1;
            dfs(i);
            nrc++;
        }
    fout<<nrc<<'\n';
    return 0;
}
void citire()
{int i, x, y;
 fin>>n>>m;
 for (i=0; i<m; i++)
     {
      fin>>x>>y;
      G[x].push_back(y);
      G[y].push_back(x);
     }
}
void dfs(int x)
{ int i;
    uz[x]=1;
    for (i=0; i<G[x].size(); i++)
        if (uz[G[x][i]]==0)
           {
            uz[G[x][i]]=1;
            dfs(G[x][i]);
           }
}