类型说明为何要放在变量说明之前．PASCAL

定义一种数据类型；
如
program lk_hls;
var
n,r,c,k,m:longint;
a:array[1..8] of integer;
b:array[1..8,1..8] of longint;
flag:array[1..8] of boolean;

procedure search(depth:integer);
var
i:integer;
begin
if(depth>n) then
begin
k:=-k div (abs(k));
for i:=1 to n do
k:=k*b[i,a[i]];
m:=m+k;
exit;
end;
for i:=1 to n do
if flag[i]=false then
begin
a[depth]:=i;
flag[i]:=true;
search(depth+1);
flag[i]:=false;
end;
end;

begin
k:=-1;
writeln('N=');
read(n);
writeln('shu ru hang lie shi:');
for r:=1 to n do
for c:=1 to n do
read(b[r,c]);
fillchar(flag,sizeof(flag),false);
search(1);
writeln(m);
end.