#include <fstream>
#include <vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
bool v[200005];
vector<int>G[100005];
void DFS(int x)
{ int i;
  v[x]=true;
  //cout<<x<<" ";
  for(auto i: G[x])
    {if (v[i]==false&& G[x][i]) DFS(i);
    }
}
int main()
{int n,m,nr=0,i,x1,x2;
    cin>>n>>m;
    for(i=1;i<=m;i++)
    {
        cin>>x1>>x2;
        G[x1].push_back(x2);
        G[x2].push_back(x1);
    }
    for(i=1;i<=n;i++)
    {if(v[i]==false)
        {DFS(i);
        nr++;
        }
    }
    cout<<nr;
    return 0;
}