#include<fstream>
#include<vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int x,y,v[100001],i,nr,n,m;
vector <int> L[100001];

void dfs(int nod){
    v[nod]=1;
    for(int i=0;i<L[nod].size();i++)
        if(v[L[nod][i]]==0)
            dfs(L[nod][i]);
}

int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++){
        f>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(v[i]==0){
            nr++;
            dfs(i);
        }
    g<<nr;
    return 0;
}