#include <fstream>
#include <bitset>
#include <vector>

using namespace std;

ifstream cin("dfs.in");
ofstream cout("dfs.out");

#define NMAX 100005

vector<int> g[NMAX];
bitset<NMAX> viz;
int n,m,i,a,b,nr;

void dfs(int nod)
{
	viz[nod] = 1;
	for(vector <int> :: iterator it = g[nod].begin() ; it != g[nod].end() ; ++ it)
		if(!viz[*it]) dfs(*it);
}

int main()
{
    cin>>n>>m;
    for(i=1;i<=m;i++)
    {
        cin>>a>>b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    for(i=1;i<=n;i++)
    {
        if(!viz[i]) {
            nr++;
            dfs(i);
        }
    }
    cout<<nr<<endl;
    return 0;
}