#include <fstream>
#define NMAX 1001
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n;
int A[NMAX][NMAX];
int uz[NMAX];
int nrc;

void citire();
void dfs(int x);

int main()
{int i;
citire();
for (i=1; i<=n; i++)
     if (!uz[i])
        {
         nrc++;
         dfs(i);
         }
fout<<nrc<<'\n';
return 0;
}
void citire()
{int i, x, y, m;
fin>>n>>m;
for (i=0; i<m; i++)
   {
     fin>>x>>y;
     A[x][0]++; A[x][A[x][0]]=y;
     A[y][0]++; A[y][A[y][0]]=x;
    }
}

void dfs(int x)
{int i;
uz[x]=1; // marchez cu 1 in vect uz, faptul ca nodul x a fost vizitat
for (i=1; i<=A[x][0]; i++)
     if (!uz[A[x][i]])
     dfs(A[x][i]);
}