#include <fstream>

using namespace std;

const int NMAX = 1e5 + 1;

struct nod
{
    int x;
    nod *next;
};

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

nod *G[NMAX];
int n, m;
bool viz[NMAX];

inline void add(int x, int y)
{
    nod *p = new nod;
    p->x = y;
    p->next = G[x];
    G[x] = p;
}

void citire()
{
    int x, y;
    fin >> n >> m;
    for(int i = 1; i <= m; ++i)
    {
        fin >> x >> y;
        add(x, y);
        add(y, x);
    }
}

void dfs(int i)
{
    viz[i] = 1;
    for(nod *p = G[i]; p != NULL; p = p->next)
        if(!viz[p->x])
            dfs(p->x);
}

int main()
{
    int sol = 0;
    citire();
    for(int i = 1; i <= n; ++i)
        if(!viz[i])
        {
            ++sol;
            dfs(i);
        }
    fout << sol;
    return 0;
}