program p1;
type lista=^celula;
      celula = record
        infor:longint;
        urm:lista;
             end;
var a:array[0..1000010] of lista;
    viz:array[0..10000] of 0..1;
    b1,b2:array[0..1 shl 17 ] of char;
    f,g:text;
    i,n,j,u,m,i_s,x,y,sol:longint;
    v:lista;
procedure dfs(nod:longint);
var r:lista;
begin
viz[nod]:=1;
r:=a[nod];
  while r<>nil do begin
                if (viz[r^.infor]=0)  then dfs(r^.infor);
                r:=r^.urm;
                end;

end;
begin
assign(f,'dfs.in');settextbuf(f,b1);reset(F);
assign(g,'dfs.out');settextbuf(g,b2);rewrite(G);
readln(f,n,m);
for i:=1 to m do
         begin
         readln(f,x,y);
         new(V);
         v^.infor:=y;
         v^.urm:=a[x];
         a[x]:=v;
         new(V);
         v^.infor:=x;
         v^.urm:=a[y];
         a[y]:=v;
         end;
for i:=1 to n do viz[i]:=0;
for i:=1 to n do
        if viz[i]=0 then begin
                        inc(sol);
                        dfs(i);
                         end;
writeln(g,sol);
close(F);
close(G);
end.