using namespace std;
#include<fstream>
#include<vector>
vector <int> l[100100];
bool v[100100];
int n;
void DFS(int nod)
{int i;
v[nod]=1;
for(i=0;i<l[nod].size();i++)
	if(!v[l[nod][i]])
		DFS(l[nod][i]);
}
void citire()
{int m,x,y,i;
ifstream in("dfs.in");
in>>n>>m;	
for(i=0;i<m;i++)
	{in>>x>>y;
	l[x].push_back(y);
	l[y].push_back(x);
	}
in.close();
}
int main()
{int cont=0,i;
citire();
for(i=1;i<=n;i++)
	if(!v[i])
		{cont++;DFS(i);}
ofstream out("dfs.out");
out<<cont<<'\n';
out.close();
return 0;
}