#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> G[100001];
int i,m,n,viz[100001],nr,x,y;
void dfs(int nod){
    viz[nod]=1;
    for(int j=0;j<G[nod].size();j++)
        if(viz[G[nod][j]]==0)
            dfs(G[nod][j]);
    }
int main()
{f>>n>>m;
for(i=1;i<=m;i++)
{
    f>>x>>y;
    G[x].push_back(y);
    G[y].push_back(x);

}

for(i=1;i<=n;i++)
    if(viz[i]==0){
        nr++;
        dfs(i);}
    g<<nr;
    return 0;
}