#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>
#define lim 100002

using namespace std;

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

int n, m, nr = 0;
vector <int> G[lim];
bitset <lim> B;

void Dfs(int vertex)
{
    B[vertex] = 1;
    for(vector <int> :: iterator it = G[vertex].begin(); it != G[vertex].end(); ++it)
        if(!B[*it])
            Dfs(*it);
}

void Read()
{
    f >> n >> m;
    int x, y;
    for(; m; --m)
    {
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

int main()
{
    Read();
    for(int i = 1 ; i <= n; ++i)
        if(!B[i])
        {
            Dfs(i);
            ++nr;
        }
    g << nr;
}