#include <bits/stdc++.h>

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector<int> v[100005];
int n,m,vis[100005],x,y,ans;
void dfs(int nod)
{
    vis[nod]=1;
    for(auto it:v[nod])
        if(vis[it]==0) dfs(it);
}
int main()
{
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(int i=1;i<=n;i++)
        if(vis[i]==0)
    {
        dfs(i);
        ans++;
    }

    out<<ans;
    return 0;
}