为什么80！！！！

var
  a:array[0..201,0..201]of longint;
  b:array[0..201]of longint; 
  n,i,j,k,sum,max:longint;
function findmax:longint;
var
  x,i,s:longint;
  begin
    x:=0;
    s:=-maxlongint;
    for i:=1 to n do 
      begin
        inc(x,b[i]);
        if x>s then s:=x;
        if x<0 then x:=0;
      end;
    exit(s);
  end;
begin
  readln(n);
  for i:=1 to n do 
    for j:=1 to n do 
      if j=n then readln(a[i,j])
        else read(a[i,j]);
  max:=-maxlongint;
  for i:=1 to n do 
    begin
      fillchar(b,sizeof(b),0);
      for j:=i to n do
        begin
          for k:=1 to n do 
            inc(b[k],a[j,k]);
          sum:=findmax;
          if sum>max then max:=sum;  
        end;
    end;
  write(max);
end.
好像是子程序问题，求dalao指点