#include <fstream>
#include <vector>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> d[100005];
int n,m,nr,x,y;
bool viz[100005];
void DFS(int k)
{
    viz[k]=1;
    for(auto it : d[k])
        if(!viz[it])
            DFS(it);
}
int main()
{
    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        d[x].push_back(y);
        d[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
        if(!viz[i])
            nr++,DFS(i);
    fout<<nr;
    return 0;
}