#include <fstream>
#include <vector>
#include <queue>
using namespace std;
vector<int> v[100010];
queue<int> q;
int viz[100010];


int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n, m, x, y, nr = 0;
    in >> n >> m;
    for(int i = 1; i <= m; ++i) {
      in >> x >> y;
      v[x].push_back(y);
      v[y].push_back(x);
    }
    for(int i = 1; i <= n; ++i) {
      if(!viz[i]) {
         viz[i] = 1;
         q.push(i);
         while(!q.empty()) {
            for(int j = 0; j < v[q.front()].size(); ++j) {
               if(viz[v[q.front()][j]] == 0) {
                  q.push(v[q.front()][j]);
                  viz[v[q.front()][j]] = 1;
               }
            }
            q.pop();
         }
         ++nr;
       }
    }
    out << nr;
    return 0;
}