var m,n,k,i,j,max,s:longint;
    ma:array[0..200] of longint;
    a:array[0..200,1..2] of longint;
begin
  read(n,m,k);
  for i:=1 to k do read(a[i,1],a[i,2]);
  for i:=1 to k-1 do
    for j:=i+1 to k do
      if (a[i,1]>a[j,1])or((a[i,1]=a[j,1])and(a[i,2]>a[j,2]))
        then begin
               s:=a[i,1]; a[i,1]:=a[j,1]; a[j,1]:=s;
               s:=a[i,2]; a[i,2]:=a[j,2]; a[j,2]:=s
             end;
  for i:=k downto 1 do
    begin
      max:=0;
      for j:=i+1 to k do
        if (a[j,1]>a[i,1])and(a[j,2]>a[i,2])and(ma[j]>max) then
max:=ma[j];
      ma[i]:=max+1
    end;
  writeln(round((m+n-2*ma[1]+sqrt(2)*ma[1])*100))
end.