#include <bits/stdc++.h>
#define Nmax 100005

using namespace std;

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

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

inline void DFS(int nod)
{
    viz[nod] = 1;
    for(auto it : L[nod])
        if(!viz[it])
            DFS(it);
}

int main()
{
    int i, x, y, cnt;
    fin >> n >> m;
    for(i = 1; i <= m; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    cnt = 0;
    for(i = 1; i <= n; i++)
        if(!viz[i])
        {
            cnt++;
            DFS(i);
        }
    fout << cnt << "\n";
    return 0;
}