#include <fstream>
#include <vector>
#include <bitset>
#define pb push_back
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int n, m, x, y, sol=0;
bitset < 100005 > viz;
vector < int > G[100005];

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

int main()
{
    f>>n>>m;
    for (int i=1; i<=m; ++i)
        f>>x>>y, G[x].pb(y), G[y].pb(x);

    for (int i=1; i<=n; ++i)
        if (!viz[i])
            dfs(i), ++sol;

    g<<sol<<'\n';
    return 0;
}