#include<fstream>
#include<vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
int n,m,nr,viz[100005],x,y;
vector <int> v[100005];
void dfs (int x)
{
    viz[x]=1;
    for(int i=0;i<v[x].size();i++)
    {
        int y=v[x][i];
        if(viz[y]==0)
            dfs(y);
    }
}
int main ()
{
    cin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(viz[i]==0)
        {
            nr++;
            dfs(i);
        }
    cout<<nr;
    return 0;
}