#include <fstream>
#include <vector>
#define len 100010
#define pb push_back

using namespace std;

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

vector<unsigned> v[len];

unsigned N, M, count;
bool viz[len];

void dfs(unsigned nod)
{
    viz[nod] = true;
    for(unsigned k = 0; k < v[nod].size(); ++k)
        if(!viz[v[nod][k]])
            dfs(v[nod][k]);
}

int main()
{
    in >> N >> M;
    for(unsigned k = 0; k < M; ++k)
    {
        unsigned x, y;
        in >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }
    for(unsigned k = 1; k <= N; ++k)
        if(!viz[k])
        {
            ++count;
            dfs(k);
        }
    out << count;
    return 0;
}