#include <fstream>
#include <vector>

using namespace std;

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

const int N = 100000;

int n, m, viz[N+1], cnt;
vector <int> a[N+1];

void dfs(int x)
{
    viz[x] = 1;
    for(int auto i: a[x])
    {
        if (!viz[i])
        {
            dfs(i);
        }
    }
}

int main()
{
    in >> n >> m;
    for(int i = 0; i < m; i++)
    {
        int x, y;
        in >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for (int i = 1; i <= n; ++i)
    {
        if (!viz[i])
        {
            cnt++;
            dfs(i);
        }
    }
    in.close();
    out.close();
    return 0;
}