#include <iostream>
#include <fstream>
#include <vector>

using namespace std;
int n,m;
vector<vector<int>> graf;
vector<int> visited;
ifstream in("dfs.in");
ofstream out("dfs.out");
void dfs(int node)
{
    visited[node] = 1;
    for (int i = 0; i < graf[node].size(); i++)
    {
        int neighbour = graf[node][i];
        if (!visited[neighbour])
            dfs(neighbour);
    }
        
}

int main()
{
    in >> n >> m;
    graf.resize(n+1);
    visited.resize(n+1, 0);
    int x,y;
    for (int i = 0; i < m; i++)
    {
        in >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    int nrconex = 0;
    for (int i = 1; i <= n; i++)
    {
        if (!visited[i])
        {
            nrconex++;
            dfs(i);
        }
    }

    out << nrconex;

    

}