#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> a[200000];
int n,i,x,y,m,nr,v[100000];
void DFS(int x)
{
    v[x]=1;
    for(int i=0 ; i<a[x].size() ; ++i)
        if(v[a[x][i]]==0)
         DFS(a[x][i]);
}
int main()
{
    f>>n>>m;
    for(i=1 ; i<=m ; ++i)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    nr=0;
    for(i=1 ; i<=n ; ++i)
        if(v[i]==0)
    {
        DFS(i);
        nr++;
    }
    g<<nr<<'\n';
}








/*#include <fstream>
using namespace std;
ifstream f("p.in");
ofstream g("p.out");
int n,i,j,x,p,u,y,v[100],a[100][100],c[100];
int main()
{
    f>>n;
    for(i=1 ; i<=n ; ++i)
        for(j=1 ; j<=n ; ++j)
         f>>a[i][j];
    x=1;
    c[1]=x;
    v[x]=1;
    p=1;
    u=1;
    while(p>0)
    {
        y=c[p];
        for(i=1 ; i<=n ; ++i)
            if(v[i]==0&&a[i][y]==1)
        {
            u++;
            c[u]=i;
            v[i]=1;
            break;
        }
        if(i>n)p--;
        else p=u;
    }
    for(i=1 ; i<=u ; ++i)
        g<<c[i]<<" ";
    g<<'\n';
    return 0;
}
//lungime


*/



/*#include <fstream>
using namespace std;
ifstream f("p.in");
ofstream g("p.out");
int n,i,j,x,p,u,y,v[100],a[100][100],c[100];
int main()
{
    f>>n;
    for(i=1 ; i<=n ; ++i)
        for(j=1 ; j<=n ; ++j)
         f>>a[i][j];
    x=1;
    c[1]=x;
    v[x]=1;
    p=1;
    u=1;
    while(p<=u)
    {
        y=c[p];
        for(i=1 ; i<=n ; ++i)
            if(v[i]==0&&a[i][y]==1)
        {
            u++;
            c[u]=i;
            v[i]=1;
        }
        p++;
    }
    for(i=1 ; i<=u ; ++i)
        g<<c[i]<<" ";
    g<<'\n';
    return 0;
}
//latime
*/
/*
7
0 0 1 0 0 0 1
0 0 0 1 0 0 0
1 0 0 1 1 0 0
0 1 1 0 1 1 0
0 0 1 1 0 1 1
0 0 0 1 1 0 1
1 0 0 0 0 1 0
*/