#include<fstream>
#include<algorithm>
#include<vector>
using namespace std;
const int NMAX=100004;
vector<int> v[NMAX];
bool w[NMAX];
void dfs(int nod)
{
    int i;
    w[nod]=1;
    for(i=0;i<v[nod].size();++i)
        if(w[v[nod][i]])
        dfs(v[nod][i]);
}
int main()
{
    int n,m,i,ans=0,x,y;
    ifstream cin("dfs.in");
    ofstream cout("dfs.out");
    cin>>n>>m;
    for(i=1;i<=m;++i)
    {
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;++i)
        if(!w[i])
        {
        ++ans;
        dfs(i);
        }
    cout<<ans;
}