Program Cifra;
type tab = array[1..99] of byte;
var t:1..30000;
i,s,l,x,j,k:byte;
a:tab;
code:integer;
c,nr:string;
f,g:text;
function pow(n,p:longint):longint;
var i,s:longint;
begin
s:=1;
for i:=1 to p do begin
 s:= s * n;
 s:= s mod 10;
end;
pow:=s;
end;
procedure gener(var a:tab);
var i: byte;
begin
 for i:=1 to 99 do begin
  if i<>1 then
   a[i]:=a[i-1]+pow(i,i)
   else
   a[i]:= pow(i,i);
   a[i]:= a[i] mod 10;
   end;
   for i:=1 to 99 do
   //write(a[i],' ');
end;
begin
assign(f,'cifra.in');assign(g,'cifra.out');
reset(f);rewrite(g);
gener(a);
readln(f,t);
for j:=1 to t do begin
 readln(f,nr);
 l:=length(nr);
  val(nr[l-1],x,code);
  val(nr[l],k,code);
  k:=k+x*10;
 writeln(g,a[k]);
end;
close(f);close(g);
end.