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

#define NMax 100000

ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector < int > v[NMax];
int ap[NMax], n, m;

int DFS(int k)
{
    ap[k] = 1;
    for(unsigned int i = 0; i < v[k].size(); i++)
    {
        if(!ap[v[k][i]])
            DFS(v[k][i]);
    }
}

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