#include<fstream>
#include<vector>
using namespace std;
int viz[100005];
vector<int> v[100005];

void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0;i<v[nod].size();++i)
    {
        if(!viz[v[nod][i]])
            dfs(v[nod][i]);
    }
}
int main()
{
    ifstream cin("dfs.in");
    ofstream cout("dfs.out");
    int n,m,s=0;
    cin>>n>>m;
    for(int i=1;i<=m;++i)
    {
        int x,y;
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
    {
        if(viz[i]==0)
        {
            ++s;
            dfs(i);
        }
    }
    cout<<s;
    return 0;
}