#include <bits/stdc++.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n, k, rez, bif[100005];
vector<int> v[100005];
void dfs(int i)
{
    bif[i] = 1;
    for (auto j : v[i])
        if (!bif[j])
            dfs(j);
}
int main()
{
    f >> n >> k;
    for (int a, b; k; k--)
    {
        f >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for (int i = 1; i <= n; i++)
        if (!bif[i])
        {
            rez++;
            dfs(i);
        }
    g << rez;
}