My code:

Program t1109;

Const MaxN=1000;
      MaxK=500000;

Var   A,B       :array[1..MaxN]of integer;
      AU,BU     :array[1..MaxN]of integer;
      Ver       :array[1..MaxK,1..2]of integer;
      M,N,K,i   :integer;
      Mi,Ni     :integer;
      Ans       :integer;
      ex        :boolean;

Function Max(A,B:integer):integer;
 begin
  If A>B then Max:=A else Max:=B;
 end;

begin
 FillChar(A,SizeOf(A),0);
 FillChar(B,SizeOf(B),0);
 FillChar(AU,SizeOf(AU),0);
 FillChar(BU,SizeOf(BU),0);
 Read(N,M,K);
 for i:=1 to K do begin
   read(ver[i,1],ver[i,2]);
   inc(a[ver[i,1]]);
   inc(b[ver[i,2]]);
  end;
 Ans:=0;
 Ni:=N;
 Mi:=M;
 repeat
 ex:=true;
 for i:=1 to K do
  if a[ver[i,1]]=1 then
   if AU[ver[i,1]]=0 then begin
    Ans:=Ans+1;
    if BU[ver[i,2]]=0 then dec(Mi);
    BU[ver[i,2]]:=1;
    AU[ver[i,1]]:=1;
    dec(a[ver[i,1]]);
    dec(b[ver[i,2]]);
    dec(Ni);
    ex:=false;
   end;
 for i:=1 to K do
  if AU[ver[i,1]]=1 then
   if BU[ver[i,2]]=0 then begin
    ex:=false;
    if B[ver[i,2]]=1 then begin
      Ans:=Ans+1;
      BU[ver[i,2]]:=1;
      dec(Mi);
     end;
    dec(a[ver[i,1]]);
    dec(b[ver[i,2]]);
   end;
 for i:=1 to K do
  if b[ver[i,2]]=1 then
   if BU[ver[i,2]]=0 then begin
    Ans:=Ans+1;
    if AU[ver[i,1]]=0 then dec(Ni);
    AU[ver[i,1]]:=1;
    BU[ver[i,2]]:=1;
    dec(a[ver[i,1]]);
    dec(b[ver[i,2]]);
    dec(Mi);
    ex:=false;
   end;
 for i:=1 to K do
  if BU[ver[i,2]]=1 then
   if AU[ver[i,1]]=0 then begin
    ex:=false;
    if A[ver[i,1]]=1 then begin
      Ans:=Ans+1;
      AU[ver[i,1]]:=1;
      dec(Ni);
     end;
    dec(a[ver[i,1]]);
    dec(b[ver[i,2]]);
   end;
 until ex;
 Ans:=Ans+Max(Mi,Ni);
 Writeln(Ans);
end.

Try this test case:
5 5 12
1 1
1 2
1 3
2 1
2 4
2 5
3 1
3 2
4 3
4 4
4 5
5 1

The answer of your program is 8, while the correct output is 5.

Hope this will help.

Good luck!

> Try this test case:
> 5 5 12
> 1 1
> 1 2
> 1 3
> 2 1
> 2 4
> 2 5
> 3 1
> 3 2
> 4 3
> 4 4
> 4 5
> 5 1
>
> The answer of your program is 8, while the correct output is 5.
>
> Hope this will help.
>
> Good luck!
>
>