#include <iostream>
#include <vector>
#include <fstream>
using namespace std;

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

vector<int> L[100001];
int vis[100001];

void dfs(int node)
{
    vector<int> st;
    st.push_back(node);
    vis[node] = 1;

    for (auto vec : L[crt])
    {
        if (vis[vec] == 0)
        {
            vis[vec] = 1;
            st.push_back(vec);
        }
    }
}

int main()
{
    int n, m;
    fin >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x); 
    }
    int nr = 0;
    for (int i = 1; i <= n; i++)
    {
        if (vis[i] == 0)
        {
            nr++;
            dfs(i);
        }
    }
    fout << nr;

    return 0;
}