#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

int n, m, nr;
vector <int> v[100005];
int used[100005];

void dfs(int x)
{
    used[x] = 1;
    for(auto it: v[x])
    {
        if(!used[it])
            dfs(it);
    }
}

int main()
{
    f >> n >> m;
    for(int i = 1 ; i <= m ; i++)
    {
        int x,y;
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(int i = 1 ; i <= n ; i++)
    {
        if(!used[i])
        {
            dfs(i);
            nr++;
        }
    }

    g << nr;
    return 0;
}