#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,d[100009],ans,x,y;
vector <int> v[100009];
void dfs(int nod)
{
    d[nod]=1;
    for(auto it : v[nod])
    {
        if(!d[it])
            dfs(it);
    }
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        if(!d[i])
        {
            ans++;
            dfs(i);
        }
    }
    fout<<ans;
    return 0;
}