var M7,M2,M14,MAX,dat,res,i,N: longint;
begin
M7 := 0;
M2 := 0;
M14 := 0;
MAX := 0;
readln(N);
for i := 1 to N do
begin
readln(dat);
if ((dat mod 7) = 0) and ((dat mod 2) > 0) and (dat > M7) then
M7 := dat;
if ((dat mod 2) = 0) and ((dat mod 7) > 0) and (dat > M2) then
M2 := dat;
if (dat mod 14 = 0) and (dat > M14) then
begin
if M14 > MAX then MAX := M14;
M14 := dat
end
else
if dat > MAX then
MAX := dat;
end;
if (M7*M2 < M14*MAX) then
res := M14*MAX
else
res := M7*M2;
writeln(res);
end.
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