{
TASK:sum
LANG:PASCAL
}
var a,b,c,d,i,j,br,n,s,l:integer;
v:array[1..100] of integer;
x:array[1..100] of integer;
begin
br:=0;
read(n);
for i:=1 to n do read(v[i]);
for i:=1 to n do
for j:=i to n do
begin
if v[i]=v[j] then inc(br);
end;
INC(BR);
s:=1;l:=n;
for i:=n-1 downto 1 do
begin
s:=s*(l-1);
l:=l-1;
end;
WRITELN(S+BR);
end.
