var n,i,ans:longint;
     a,r:array[0..1000000]of longint;
procedure msort(s,t:longint);
var i,j,k,m:longint;
begin
 if s=t then exit;
 m:=(s+t)div 2;
 msort(s,m);
 msort(m+1,t);
 i:=s; j:=m+1; k:=s;
 while (i<=m)and(j<=t) do begin
  if a[i]<=a[j] then begin r[k]:=a[i]; inc(i); inc(k); end
  else begin r[k]:=a[j]; inc(j); inc(k); inc(ans,m-i+1);end;
 end;
 while i<=m do begin r[k]:=a[i]; inc(k); inc(i);end;
 while j<=t do begin r[k]:=a[j]; inc(k); inc(j);end;
 for i:=s to t do  a[i]:=r[i];
end;
begin
 readln(n);
 for i:=1 to n do read(a[i]);
 msort(1,n);
 //for i:=1 to n do write(a[i],' ');
 writeln(ans);
  close(input);
  close(output);
end.