Program Sea_Battle;
Var i,j,k,x,y,m,n,tot,ans:longint;
d:array[1..30,1..4] of longint;
a:array[1..2000,1..4] of longint;
s:string;
Procedure Cut(x1,y1,x2,y2:longint);
Var i,j,k,L,bj,x,y:longint;
xx,k1:longint;
Begin
j:=0;
k1:=tot;
while j<k1 do
begin
inc(j);
if (a[j,1]>=x1)and(a[j,2]>=y1)and
(a[j,3]<=x2)and(a[j,4]<=y2) then
begin
for L:=1 to 4 do a[j,L]:=0;
end
else
begin
bj:=0;
if (x1>=a[j,1])and(x1<=a[j,3])and
(((y1>=a[j,2])and(y1<=a[j,4]))or
((y2>=a[j,2])and(y2<=a[j,4]))or
((y1<=a[j,2])and(y2>=a[j,4]))) then bj:=1;
if (x2>=a[j,1])and(x2<=a[j,3])and
(((y1>=a[j,2])and(y1<=a[j,4]))or
((y2>=a[j,2])and(y2<=a[j,4]))or
((y1<=a[j,2])and(y2>=a[j,4]))) then
begin
if bj=0 then bj:=2
else
begin
inc(tot);
a[tot]:=a[j];
a[tot,1]:=x2+1;
end;
end;
if (y1>=a[j,2])and(y1<=a[j,4])and
(((x1>=a[j,1])and(x1<=a[j,3]))or
((x2>=a[j,1])and(x2<=a[j,3]))or
((x1<=a[j,1])and(x2>=a[j,3]))) then
begin
if (x1<=a[j,1])and(x2>=a[j,3])and(bj=0) then bj:=3
else
begin
if x1<a[j,1] then x:=a[j,1]
else x:=x1;
if x2<a[j,3] then xx:=x2
else xx:=a[j,3];
inc(tot);
a[tot]:=a[j];
a[tot,1]:=x;
a[tot,4]:=y1-1;
a[tot,3]:=xx;
end;
end;
if (y2>=a[j,2])and(y2<=a[j,4])and
(((x1>=a[j,1])and(x1<=a[j,3]))or
((x2>=a[j,1])and(x2<=a[j,3]))or
((x1<=a[j,1])and(x2>=a[j,3]))) then
begin
if (x1<=a[j,1])and(x2>=a[j,3])and(bj=0) then bj:=4
else
begin
if x1<a[j,1] then x:=a[j,1]
else x:=x1;
if x2<a[j,3] then xx:=x2
else xx:=a[j,3];
inc(tot);
a[tot]:=a[j];
a[tot,1]:=x;
a[tot,2]:=y2+1;
a[tot,3]:=xx;
end;
end;
case bj of
1:begin
a[j,3]:=x1-1;
end;
2:begin
a[j,1]:=x2+1;
end;
3:begin
if x1<a[j,1] then x:=a[j,1]
else x:=x1;
if x2<a[j,3] then xx:=x2
else xx:=a[j,3];
a[j,1]:=x;
a[j,4]:=y1-1;
a[j,3]:=xx;
end;
4:begin
if x1<a[j,1] then x:=a[j,1]
else x:=x1;
if x2<a[j,3] then xx:=x2
else xx:=a[j,3];
a[j,1]:=x;
a[j,2]:=y2+1;
a[j,3]:=xx;
end
end;
end;
end;
inc(tot);
a[tot,1]:=x1;
a[tot,2]:=y1;
a[tot,3]:=x2;
a[tot,4]:=y2;
End;
Procedure Search(z:longint);
Var i,j,k,x1,y1,x2,y2:longint;
Begin
for i:=1 to n do
begin
if z=1 then
begin
x1:=d[i,1]-1;
y1:=d[i,2]-m;
if d[i,4]=1 then x2:=d[i,1]+1
else x2:=d[i,1]+d[i,3];
if d[i,4]=0 then y2:=d[i,2]+1
else y2:=d[i,2]+d[i,3];
end
else
begin
x1:=d[i,1]-m;
y1:=d[i,2]-1;
if d[i,4]=1 then x2:=d[i,1]+1
else x2:=d[i,1]+d[i,3];
if d[i,4]=0 then y2:=d[i,2]+1
else y2:=d[i,2]+d[i,3];
end;
if x1<1 then x1:=1;
if y1<1 then y1:=1;
if x2>x then x2:=x;
if y2>y then y2:=y;
Cut(x1,y1,x2,y2);
end;
for i:=1 to tot do
if (a[i,1]<>0)and((a[i,3]-a[i,1]+1)*
(a[i,4]-a[i,2]+1)>0) then
ans:=ans-(a[i,3]-a[i,1]+1)*
(a[i,4]-a[i,2]+1);
End;
Begin
readln(x,y,n);
ans:=x*y*2;
fillchar(d,
