function soucet(a : longint) : integer; var b : longint; begin b := 0; while a >= 10 do begin b := b + a mod 10; a := a div 10; end; b := b + a; soucet := b; end; var maxX, maxY, pocet, x, y, i, j : integer; vystup : longint; radek, sloupec, diag1, diag2 : array[1..40000] of byte; begin read(maxX); read(maxY); readln(pocet); while maxX <> 0 do begin vystup := 0; for i := 1 to maxX do begin radek[i] := 0; end; for i := 1 to maxY do begin sloupec[i] := 0; end; for i := 1 to maxX + maxY - 1 do begin diag1[i] := 0; diag2[i] := 0; end; for i := 1 to pocet do begin read(x); readln(y); sloupec[x] := 1; radek[y] := 1; diag1[x + maxY - y] := 1; diag2[x + y - 1] := 1; end; for i := 1 to maxX do begin for j := 1 to maxY do begin if (sloupec[i] = 0) and (radek[j] = 0) then begin if (diag1[i + maxY - j] = 0) and (diag2[i + j - 1] = 0) then begin inc(vystup); end; end; end; end; writeln(vystup); read(maxX); read(maxY); readln(pocet); end; end.