#include <fstream>
#include <queue>
#include <vector>
#define nmax 100005

using namespace std;

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

int n,m;
bool viz[nmax];
vector <int> V[nmax];

void Citire()
{int i,x,y;
fin>>n>>m;
for(i=1;i<=m;i++)
    {fin>>x>>y;
     V[x].push_back(y);
     V[y].push_back(x);
    }
}


void DFS(int x)
{int i;
vector <int>::iterator it;
viz[x]=1;
for(it=V[x].begin();it!=V[x].end();it++)
     if(!viz[*it]) DFS(*it);
}


int main()
{int i,nr=0;
vector <int>::iterator it;
Citire();
for(i=1;i<=n;i++)
    if(viz[i]==0)
      {nr++;
       DFS(i);
      }
fout<<nr;

    return 0;
}