#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int Viz[100001],n,m;
vector <int> L[100001];
void Citire()
{ int i,x,y;
    f>>n>>m;
    for(i=1;i<=m;i++)
    {f>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
}
void DFS(int nod)
{Viz[nod]=1;
int i,vec;
for(i=0;i<L[nod].size();i++)
  if(Viz[L[nod][i]]==0)
  {vec=L[nod][i];
    DFS(vec);
  }
}

int main()
{int j,nr=0;
Citire();
for(j=1;j<=n;j++)
  if(Viz[j]==0)
 { DFS(j);
    nr++;
 }
g<<nr;
f.close();
g.close();
    return 0;
}