#include <fstream>
#include <vector>
#define NMAX 1000001
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
int n,start,nrc;
bool viz[NMAX];
vector<int> A[NMAX]; //am declart un vector cu NMAX elemente de tip vector din stl cu 0 elem de tip int numit A
void citire();
void afisare();
void dfs(int x);
int main()
{
    citire();
    for (int i=1; i<=n; i++)
        if (viz[i]==0)
    {
        nrc++;
        dfs(i);
    }
    fout<<nrc;
    return 0;
}
void citire()
{   int i,m,x,y;
    fin>>n>>m;
    for (i=0; i<m; i++)
    {
        fin>>x>>y;
        //adaug pe y in lista de adiacenta a lui x
        A[x].push_back(y);

        A[y].push_back(x);
    }
}
void afisare()
{   int i,j;
    for (i=1; i<=n; i++)
        {for (j=0; j<A[i].size(); j++)
            fout<<A[i][j]<<' ';
            fout<<'\n';
        }
}
void dfs(int x)
//parcurg graful incepand din vf x
{   int i;
    viz[x]=1;
    for (i=0; i<A[x].size(); i++)
        if (!viz[A[x][i]]) //exista muchia [x,A[x][i]]/(x,A[x][i])
            dfs(A[x][i]);
}