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

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int n, m, use[100005], contor;
vector <int> G[100005];

void DFS(int nod)
{
    use[nod] = 1;
    for(int i = 0; i < (int)G[nod].size(); i++)
    {
        int vecin = G[nod][i];
        if(!use[vecin]) DFS(vecin);
    }
}

int main()
{
    f>>n>>m;
    for(int i = 1; i <= m; i++)
    {
        int x,y;
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
        if(use[i] == 0) DFS(i), contor++;
    g<<contor<<'\n';
    return 0;
}