A decimal number can be converted to its
Hexspeak representation
by first converting it to an uppercase hexadecimal string, then replacing all occurrences of the digit
0
with the letter
O
, and the digit
1
with the letter
I
. Such a representation is
valid
if and only if it consists only of the letters in the set
{"A", "B", "C", "D", "E", "F", "I", "O"}
.
Given a string
num
representing a decimal integer
N
, return the Hexspeak representation of
N
if it is valid, otherwise return
"ERROR"
.
Example 1:
Input: num = "257" Output: "IOI" Explanation: 257 is 101 in hexadecimal.
Example 2:
Input: num = "3" Output: "ERROR"
Constraints:
1 <= N <= 10^12