#include <fstream>
#include <vector>
#define NMAX 100005
#define pb push_back

using namespace std;

ifstream cin("dfs.in");
ofstream cout("dfs.out");

vector<int> adj[NMAX];
bool vis[NMAX];
int n,m,x,y,cnt;
void dfs(int nod)
{
    vis[nod] = 1;
    for(int k=0; k < adj[nod].size(); k++)
    {
        if(!vis[adj[nod][k]])
            vis[adj[nod][k]] = 1 , dfs(adj[nod][k]);
    }
}
int main()
{
    cin >> n >> m;
    for(int i=1; i <= m; i++)
    {
        cin >> x >> y;
        adj[x].pb(y);
        adj[y].pb(x);
    }
    for(int i=1; i <= n; i++)
    {
        if(!vis[i])
            dfs(i) , cnt++;
    }
    cout << cnt;
    return 0;
}