记录编号	39345	评测结果	AAAAAAAAAA
题目名称	数列	最终得分	100
用户昵称	wo shi 刘畅	是否通过	通过
代码语言	Pascal	运行时间	0.065 s
提交时间	2012-07-09 15:11:36	内存使用	38.31 MiB

var
  i:longint;
  ans,n:int64;
  a,f,s,zuo,you:Array[0..1000000]of int64;

function lowbit(k:int64):int64;
begin
  lowbit:=k and (-k);
end;

function lowbi(k:int64):int64;
begin
  lowbi:=k and (-k);
end;

procedure change(k,x:int64);
begin
  while k<=32768 do
  begin
    inc(f[k],x);
    inc(k,lowbit(k));
  end;
end;

procedure chang(k,x:int64);
begin
  while k<=32768 do
  begin
    inc(s[k],x);
    inc(k,lowbi(k));
  end;
end;

function sum(k:int64):int64;
var
  num:int64;
begin
  num:=0;
  while k>0 do
  begin
    inc(num,f[k]);
    dec(k,lowbit(k));
  end;
  sum:=num;
end;

function su(k:int64):int64;
var
  num:int64;
begin
  num:=0;
  while k>0 do
  begin
    inc(num,s[k]);
    dec(k,lowbit(k));
  end;
  su:=num;
end;

begin
  assign(input,'queueb.in'); reset(input);
  assign(output,'queueb.out'); rewrite(output);
  readln(n);
  for i:=1 to n do
  begin
    read(a[i]);
    inc(a[i]);
  end;
  change(a[1],1);
  for i:=2 to n do
  begin
    zuo[i]:=sum(a[i]-1);
    change(a[i],1);
  end;
  chang(a[n],1);
  for i:=n-1 downto 1 do
  begin
    you[i]:=su(a[i]-1);
    chang(a[i],1);
  end;
  ans:=0;
  for i:=2 to n-1 do ans:=ans+zuo[i]*you[i];
  writeln(ans);
  close(input);
  close(output);
end.