#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, ncc, cc, i, j, x, y;
vector <vector <int> > s;
vector <int> v;
void dfs(int x)
{
    v[x] = cc;
    for (auto it : s[x])
    {
        if (v[it] == 0)
            dfs(it);
    }
}
int main()
{
    fin >> n >> m;
    s.resize(n+1);
    v.resize(n+1);
    for (i = 1; i <= m; i++)
    {
        fin >> x >> y;
        s[x].push_back(y);
        s[y].push_back(x);
    }
    
    for (i = 1; i <= n; i++)
        if (v[i] == 0)
        {
            cc++;
            dfs(i);
        }
    fout << cc;
    return 0;
}