#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
#define MAX 100010

typedef vector<int> :: iterator iter;
vector <int> G[MAX];
int viz[MAX], n, m, x, y, i, s;
void df(int nod)
{
    viz[nod] = 1;
    for(iter it = G[nod].begin() ; it != G[nod].end() ; it++)
    {
        if(!viz[*it])
            df(*it);
    }
}

int main()
{
    fin >> n >> m;
    while(m--)
    {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(i = 1 ; i <= n ; i++)
    {
        if(!viz[i])
        {
            s++;
            df(i);
        }
    }
    fout << s << "\n";
}