#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> graph[100001];
int i, Nods, Arcs, Origins, x, y, ConexNr, viz[100001];
void dfs(int node){
    viz[node] = ConexNr;
    for(int i = 0; i < graph[node].size(); i++)
        if(viz[graph[node][i]] == 0)
            dfs(graph[node][i]);
}
int main()
{   f >> Nods >> Arcs;
    for(i = 1; i <= Arcs; i++){
        f >> x >> y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    for(i = 1; i <= Nods; i++){
        if(viz[i] == 0){
            ConexNr++;
            dfs(i);
        }
    }
    g << ConexNr;
    return 0;
}