var t,te:text;
    teste,i:integer;
    x:array[0..9] of byte;
    a,b,c:char;
    ok:boolean;

begin
assign(t,'cifra.in'); reset(t);
assign(te,'cifra.out'); rewrite(te);
readln(t,teste);
x[0]:=0;
x[1]:=1;
x[2]:=5;
x[3]:=4;
x[4]:=0;
x[5]:=5;
x[6]:=1;
x[7]:=0;
x[8]:=4;
x[9]:=5;
for i:=1 to teste do
  begin
    ok:=false;
    while (not(eoln(t))) do begin read(t,a); if eoln(t) then begin ok:=true; break; end; read(t,b); end;
    if ok then
      begin
        c:=a;
        a:=b;
        b:=c;
      end;
    writeln(te,(((ord(a)-48) mod 2)*5+x[ord(b)-48]) mod 10);
    readln(t);
  end;
close(te);
end.