#include <fstream>
#include<vector>
using namespace std;
const int n_max=100005;
int m, n, viz[n_max];
vector<int>v[n_max];
//vector <int>:: iterator it;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

void citire()
{ fin>>n>>m;
for(int i=1;i<=m;i++)
{ int x,y;
fin>>x>>y;
v[x].push_back(y);
v[y].push_back(x);
}
}
void dfs(int nod)
{ viz[nod]=1;
for(int i=0;i<v[nod].size();++i)
    if(viz[v[nod][i]]==0)
          dfs(v[nod][i]);

}
int main()
{ citire();
int contor=0;
for(int i=1;i<=n;i++)
if(viz[i]==0)

{ contor++;
dfs(i);
}
fout<<contor;
return 0;}