#include <bits/stdc++.h>

using namespace std;

const int N=100000+5;

int n,m;
vector<int>g[N];
bool viz[N];

inline void roflan(int nod)
{
    viz[nod]=1;
    for(auto &nou:g[nod])
    {
        if(viz[nou]==0)
        {
            roflan(nou);
        }
    }
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    cin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int a,b;
        cin>>a>>b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    int ans=0;
    for(int i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            ans++;
            roflan(i);
        }
    }
    cout<<ans<<"\n";
    return 0;
}