#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
vector <int > v[100005];
queue <int > coada;
bool incoada[100005];
int n, m, comp;
void citire()
{fin >> n >> m;
 int a, b;
 for (int i=1;i<=m;i++)
     {fin >> a >> b;
      v[a].push_back(b);
      v[b].push_back(a);
     }
}
void dfs (int k)
{incoada[k]=true;
 for (int i=0;i<v[k].size();i++)
        if(incoada[v[k][i]]==false)dfs(v[k][i]);
}
int main()
{citire ();
 for (int i=1;i<=n;i++)
     {if(incoada[i]==false)
        {dfs(i);
         comp++;
        }
     }
     fout << comp;
    return 0;
}