var

i, min: integer;

a: array[1..20] of integer;

begin

min:= 1000000000;

for i:= 1 to 20 do

begin

   readln(a[i]);

   if (a[i] < min) and (a[i] mod 7 <> 0) then

       min:= a[i];

end;

writeln(min);

end.