#include <fstream>
#include <vector>
#include <bitset>
#define nmax 100002
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

int cmp,n,m,x,y;
vector <int> graf[nmax];
bitset <nmax> v;

void comp(int nod)
{
    v[nod]=1;
    int lg=graf[nod].size();
    for(int i=0;i<lg;i++)
        if(!v[graf[nod][i]])
            comp(graf[nod][i]);
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!v[i])
            cmp++,comp(i);
    fout<<cmp;
    return 0;
}