#include <bits/stdc++.h>
#define nmax 100001

using namespace std;

ofstream fout("dfs.out");
ifstream fin("dfs.in");

int n,m,viz[nmax];
vector <int> L[nmax];

void citire()
{
    int x,y;
    fin >> n >> m;
    while(m--)
    {
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
}

void dfs(int top, int cnt)
{
    viz[top] = cnt;
    for(auto i : L[top])
        if(viz[i] == 0)
            dfs(i,cnt);
}

void afisare(int cnt)
{
    fout << cnt;
}

int main()
{
    citire();
    int i,cnt = 0;
    for(i = 1; i <= n; i++)
        if(viz[i] == 0)
        {
            cnt++;
            dfs(i,cnt);
        }
    afisare(cnt);
    fin.close();
    fout.close();
    return 0;
}