#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> vecini[100005];
int n, m;
bool viz[100005];
void DFS(int varf)
{
    viz[varf] = 1;
    for(int i = 0; i < vecini[varf].size(); i++)
    {
        if(viz[vecini[varf][i]] == 0)
        {
            DFS(vecini[varf][i]);
        }
    }
}
int main()
{
    int r = 0;
    f >> n >> m;
    int a, b;
    for(int i = 1; i <= m; i++)
    {
        f >> a >> b;
        vecini[a].push_back(b);
        vecini[b].push_back(a);
    }
    for(int i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            DFS(i);
            r++;
        }
    }
    g << r;
}