#include <fstream>
using namespace std;
int n,a[1005][1005],viz[1005],m,ncc;
ifstream in("dfs.in");
ofstream out("dfs.out");
void df(int nod)
{
    int i;
    viz[nod]=1;
    for(i=1;i<=n;i++)
        if(a[nod][i] && !viz[i])
        df(i);
}
void citire()
{
    int x,y,i;
    in>>n>>m;
    for(i=1;i<=m;i++)
    {
        in>>x>>y;
        a[x][y]=a[y][x]=1;
    }
}
int main()
{
    citire();
    int i;
    for(i=1;i<=n;i++)
        if(!viz[i])
        {
            ncc++;
            df(i);
        }
        out<<ncc<<'\n';
    return 0;
}