#include <bits/stdc++.h>
#define NMAX 100001
using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

vector <int> G[NMAX];
int n,m,c;
bool viz[NMAX];
void DFS(int nod)
{
    viz[nod]=1;
    int nrnod=G[nod].size();
    int nodc;
    for(int i=0;i < nrnod; i++)
    {
        nodc=G[nod][i];
        if(viz[nodc]==0)
            DFS(nodc);
    }
}
int main()
{
    f>>n>>m;
    int x,y;
    for(int i=1;i<=m;i++)
    {
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int nod=1;nod<=n;nod++)
    {
        if(viz[nod]==0)
        {
            c++;
            DFS(nod);
        }
    }
    g<<c;
    return 0;
}