const N=30;
var a:array[1..N] of longint;
i,j,p:longint;
begin
p:=1;
for i:=1 to N do
readln(a[i]);
for i:=1 to N do
if (a[i]>9)and(a[i]<100)and((a[i] div 10 + a[i] mod 10) mod 6=0) then p:=p*a[i];
writeln(p);
end.
var a:array[1..N] of longint;
i,j,p:longint;
begin
p:=1;
for i:=1 to N do
readln(a[i]);
for i:=1 to N do
if (a[i]>9)and(a[i]<100)and((a[i] div 10 + a[i] mod 10) mod 6=0) then p:=p*a[i];
writeln(p);
end.