#include <bits/stdc++.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
#define nmax 100003
int n,m,x,y,cnt;
int viz[nmax];
vector < int > v[nmax];
queue < int > coada;
void DFS(int nod)
{
   viz[nod]=1;
   for(vector < int > ::iterator it=v[nod].begin();it!=v[nod].end();it++)
     if(!viz[*it]) DFS(*it);
}
int main()
{
    f>>n>>m;
    for(int i=1; i<=m; i++)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
        if(!viz[i])
        {
            DFS(i);
            cnt++;
        }
    g<<cnt;
    return 0;
}