#include <iostream>
#include <fstream>
#include <vector>
#define N 100001
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");


vector <int>  vec[N];
int viz[N];

void adaug(int x, int y)
{
    vec[x].push_back(y);
}

void  dfs(int x) 
{
    viz[x] = 1;
    int l = vec[x].size();
    for (int i = 0; i < l; i++)
        if (viz[vec[x][i]] == 0)
        {
            dfs(vec[x][i]);
        }
}

int main()
{
    int n, m;
    fin >> n >> m;
    for (int i = 1; i <= m; i++) 
    {
        int x, y;
        fin >> x >> y;
        adaug(x, y);
        adaug(y, x);
    }
    int cnt = 0;
    for (int i = 1; i <= n; i++)
        if (viz[i] == 0) 
        {
            cnt++;
            dfs(i);
        }
    fout << cnt;
    return 0;
}