#include <fstream>
#include <vector>
#define NMAX 100005

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

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