#include <fstream>
#include <vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector<int>v[100000];
int seen[100000], k, n, m, x, y;
void dfs(int nod)
{
    seen[nod]=-1;
    for(int i=0; i<v[nod].size(); i++)
        if(seen[v[nod][i]]==0)
            dfs(v[nod][i]);
}
int main()
{
    in>>n>>m;
    for(int i=0; i<m; i++)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=0; i<n; i++)
        if(seen[i]==0)
        {
            k++;
            dfs(i);
        }
    out<<k;
    return 0;
}