var n,nr,p,i,j,k : longint;
    f,g : text;
    t : integer;
    c : char;
    c1,c2 : byte;
begin
assign(f,'cifra.in'); reset(f);
assign(g,'cifra.out'); rewrite(g);
readln(f,t);
for k:=1 to t do Begin
repeat
read(f,c);
c2:=c1;
c1:=ord(c)-48;
until eoln(f);
readln(f);
n:=c2*10 + c1;

      for i:=1 to n do begin
      p:=1;
              for j:=1 to i do begin
                      p:=p*i;
                      p:= p mod 10;
                      end;
      nr:=nr + p;
                       end;

writeln(g,nr mod 10);
nr:=0; c1:=0;c2:=0;
                 End;

close(g);
end.