# include <iostream>
# include <fstream>
# include <vector>
using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

# define maxn 100003

int v[maxn], n, m;
vector <int> a[maxn];

void dfs(int nod)
{
    v[nod]=1;
    int i;
    for(i=0; i<a[nod].size(); i++)
    {
        if(v[a[nod][i]]==0)
            dfs(a[nod][i]);
    }
}

int main()
{
    a[maxn].reserve(maxn);
    f>>n>>m;
    int i,x,y,nrc=0;

    for(i=1; i<=m; i++)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

    for(i=1; i<=n; i++)
    {
        if(v[i]==0)
        {
            dfs(i);
            nrc+=1;
        }
    }

    g<<nrc<<'\n';

    return 0;
}