uses crt;
var f,g:text;
    a:array[1..100] of integer;
    suma,uc,k,i,n,suma1:integer;

begin
clrscr;
assign(f,'cifra.in');
reset(f);
assign(g,'cifra.out');
rewrite(g);
read(f,n);
for i:=1 to n do read(f,a[i]);
repeat
suma1:=1;
k:=k+1;
for i:=1 to k do suma1:=suma1*a[k];
suma:=suma+suma1;
uc:=suma mod 10;
writeln(uc)
until k=n;
end.