#include <fstream>
#include <vector>

using namespace std;

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

const int N = 100005;
vector<int> adj[N];
bool vis[N];

void DFS(int s)
{
    vis[s] = 1;
    for (unsigned int i = 0; i<adj[s].size(); i++)
    {
        if (!vis[adj[s][i]])
            DFS(adj[s][i]);
    }
}

int main()
{
    int n,m,x,y,c=0;
    in >> n >> m;
    for (int i = 1; i<=m; i++)
    {
        in >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for (int i = 1; i<=n; i++)
    {
        if (!vis[i])
        {
            c++;
            DFS(i);
        }
    }
    out << c;
}