#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector<int>graph[100002];
int v[100002];
void dfs(int x)
{
    int lim,i;
    v[x]=1;
    lim=graph[x].size();
    for(i=0;i<lim;i++)
       if(v[graph[x][i]]==0)
         dfs(graph[x][i]);

}

int main()
{   int nr=0,i,m,n,x,y;
    f>>n>>m;
    for(i=1;i<=m;i++)
     {
        f>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
     }
    for(i=1;i<=n;i++)
        if(v[i]==0)
    {
        dfs(i);
        nr=nr+1;
    }

        g<<nr;


    return 0;
}