#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

int viz[100005];
vector <int> graph[100005];
void DFS(int x)
{
    viz[x]=1;
    int lim=graph[x].size();
    for(int i=0;i<lim;i++)
    {
        if(viz[graph[x][i]]==0)
            DFS(graph[x][i]);
    }
}
int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int N,M,x,y,nr_comp_conexe=0,i;
    in>>N>>M;
    for(i=0;i<M;i++)
    {
        in>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    for(i=1;i<=N;i++)
    {
        if(viz[i]==0)
        {
            DFS(i);
            nr_comp_conexe++;
        }
    }
    out<<nr_comp_conexe;
    return 0;
}