pascal 八皇后问题

PROGRAM eightqueens(input,output);{°Ë»ÊºóÎÊÌâ}
var
  x:array[1..8,1..8]of integer;
  a,b,c:array[-7..16]of boolean;
  i,m,n,count:integer;
procedure print;
  var
    k,l:integer;
    begin
      writeln('count=',count);
      for k:=1 to 8 do
        for l:=1 to 8 do
          begin
            write(x[k,l]);
            if l mod 8=0
              then writeln
          end;
      readln();
    end;
procedure try(i:integer);
  var
    j:integer;
  begin
    for j:=1 to 8 do
      if a[j] and b[i+j] and c[i-j]
        then
          begin
            x[i,j]:= 1;
            a[j]:=false;
            b[i+j]:=false;