#include <fstream>
#include <vector>
using namespace std;
vector <int>v[1000001];
bool ok[1000001];
int n,i,j,k,x,y,nr;
ifstream f("dfs.in");
ofstream g("dfs.out");
void dfs(int x)
{vector <int>::iterator it;
ok[x]=true;
for (it=v[x].begin();it!=v[x].end();it++)
if (ok[*it]==false) dfs(*it);
}
int main()
{f>>n;
f>>k;
for (i=1;i<=k;i++)
{f>>x>>y;
v[x].push_back(y);
v[y].push_back(x);
}
for (i=1;i<=n;i++)
{if (!ok[i]) {dfs(i);
              nr++;}

}
g<<nr;
}