#include <fstream>
#include <vector>

using namespace std;

ifstream cin ("dfs.in");
ofstream cout ("dfs.out");

int v[100001],n,m,comp;
vector <int> M[100001];

void dfs (int x)
{
    v[x]=1;
    for (auto i:M[x])
        if (!v[i])
            dfs(i);
}

int main()
{
    cin>>n>>m;
    for (int i=1; i<=m; ++i)
    {
        int x,y;
        cin>>x>>y;
        M[x].push_back(y);
        M[y].push_back(x);
    }
    for (int i=1; i<=n; ++i)
        if (!v[i]){
            comp++;
            dfs(i);
        }
    cout<<comp;

    return 0;
}