The king is dead, long live the king! After the sudden death of the king Fert XIII the people of the Flatland Kingdom are going to welcome the new king. Unfortunately, there is a problem, Fert has too many sons.
Actually, he has $n$ sons and he loved each new son more than all of his previous sons. Well, probably he just stopped loving his sons because of their bad behavior. Anyway, after the new son was born Fert made the new testament that declared that the newly born son would be the heir.
However, there is a problem. Only the king's son who is at least 18 years old at the moment of the king's death can become a new king. Now the ministers of the government are trying to find the correct new king, but they seem to fail. Help them!
Output
Output one integer — the number of the son that would become the king, or $-1$ if none of them is at least 18 years old. The sons are numbered from 1 to $n$ in order they are described in the input. The youngest son who is at least 18 years old at the moment of the king's death would become the king. If the son has his 18th birthday exactly on the day of the king's death, he can become a king.