#include <fstream>
#include <vector>
#define NMAX 100002
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,start,nrc;
vector<int>G[NMAX];
int uz[NMAX];
int d[NMAX];
void citire();
void dfs(int x);
void afisare();
int main()
{int i;
    citire();
    for(i=1;i<=n;i++)
        if(!uz[i])
            {
            nrc++;
            dfs(i);
            }
    afisare();
    return 0;
}
void citire()
{
int x,y,m,i=1;
    fin>>n>>m;
    while(i<=m)
        {
        fin>>x>>y;
        ///adaug pe x in lista de adiacenta a lui y
        G[y].push_back(x);
        G[x].push_back(y);
        i++;
        }
}
void dfs(int x)
{int i;
     uz[x]=nrc;
     for(i=0;i<G[x].size();i++)
        if(!uz[G[x][i]])
            dfs(G[x][i]);
}
void afisare()
{int i,j;
    fout<<nrc<<'\n';

}