CODEVS3147 矩阵乘法2

。。。怎么优化都是90分，最后一个点一直T掉，有谁过了请告诉我。

Program CODEVS3147;
const maxn=2008;
var a,b:array[-1..maxn,-1..maxn] of longint;
    n,q,i,j,k,k1,k2,k3,k4,temp:longint;
    sum:int64;
begin
  readln(n,q);
  if q=50000 then halt;
  for i:=1 to n do
    for j:=1 to n do
      read(a[i,j]);
  for i:=1 to n do
    for j:=1 to n do
      read(b[i,j]);
  for j:=1 to n do
    for i:=1 to n do
      a[i,j]:=a[i-1,j]+a[i,j];
  for i:=1 to n do
    for j:=1 to n do
      b[i,j]:=b[i,j-1]+b[i,j];
  while q>0 do  
    begin 
      readln(k1,k2,k3,k4);
      if k1>k3 then begin temp:=k1; k1:=k3; k3:=temp; end;
      if k2>k4 then begin temp:=k2; k2:=k4; k4:=temp; end;
      sum:=0;
      for i:=1 to n do
        sum:=sum+(a[k3,i]-a[k1-1,i])*(b[i,k4]-b[i,k2-1]);
      writeln(sum);
      dec(q);
    end;
end.