#include <bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n, viz[100005], k;
vector<int> L[100005];

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