记录编号	39355	评测结果	AAAAAAAAAA
题目名称	数列	最终得分	100
用户昵称	SnowDancer	是否通过	通过
代码语言	Pascal	运行时间	0.040 s
提交时间	2012-07-09 15:14:13	内存使用	0.85 MiB

var
  n,i,j,k,l:longint;
  num:array[1..100000] of longint;
  tree:array[0..1,1..40000] of longint;
  ans:int64;
procedure add(code,k,delta:longint);
  begin
    while k<40000 do begin
      inc(tree[code,k],delta);
      k:=k+k and (-k);
    end;
  end;
function sum(code,k:longint):int64;
  var
    ans:int64;
  begin
    ans:=0;
    while k>0 do begin
      inc(ans,tree[code,k]);
      k:=k-k and (-k);
    end;
    exit(ans);
  end;
begin
assign(input,'queueb.in'); reset(input);
assign(output,'queueb.out'); rewrite(output);
  readln(n);
  for i:=1 to n do begin
    readln(num[i]);
    inc(num[i]);
  end;
  for i:=2 to n do add(1,num[i],1);
  for i:=2 to n-1 do begin
    add(0,num[i-1],1);
    add(1,num[i],-1);
    inc(ans,sum(0,num[i]-1)*sum(1,num[i]-1));
  end;
  writeln(ans);
close(input); close(output);
end.