#include <bits/stdc++.h>
using namespace std;
int n,m,i,j,seen[100005],ans;
vector<int>g[100005];
void dfs(int u)
{
    seen[u]=1;
    for (auto v : g[u])
    {
        if (!seen[v])
        {
            dfs(v);
        }
    }
}
int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    cin.tie(0); cout.tie(0);
    ios_base::sync_with_stdio(false);

    cin>>n,m;
    while (m--)
    {
        cin>>i>>j;
        g[i].push_back(j);
        g[j].push_back(i);
    }
    for (i=1; i<=n; i++)
    {
        if (!seen[i])
        {
            ans++;
            dfs(i);
        }
    }
    cout<<ans;
}