List isn't necessary as sorted takes any object iirc

print raw_input()==0 or sorted(set(map(int, raw_input().split())))[-2]

For those that didn't understand, first input isn't actually necessary because validation of the length of the numbers entered in 2nd line isn't actually being asked

raw_input returns type string, hence it will never be zero(0) and won't print the first input under any circumstance.

Next read the input,split away the spaces and map it to integer type

Make it's set

Sort the set

Print the 2nd last element in the sorted set