#include <fstream>
#include <stack>
#include <vector>
#include <bitset>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
int n,m,x,y,i,componente;
vector <int> a[100001];
stack <int> stiva;
bitset <100001> viz;
void dfs(int node)
{
    stiva.push(node);
    viz[node]=1;
    for (int i=0;i<a[node].size();++i)
    {
        if (!viz[a[node][i]])
            dfs(a[node][i]);
    }
    stiva.pop();

}
int main()
{
    in>>n>>m;
    while (m)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
        m--;
    }
    for (i=1;i<=n;++i)
    {
        if (!viz[i]) componente++,dfs(i);
    }
    out<<componente<<"\n";
}