#D6163. High Elements
High Elements
High Elements
You are given P, a permutation of (1,\ 2,\ ...\ N).
A string S of length N consisting of 0
and 1
is a good string when it meets the following criterion:
- The sequences X and Y are constructed as follows:
- First, let X and Y be empty sequences.
- For each i=1,\ 2,\ ...\ N, in this order, append P_i to the end of X if S_i=
0
, and append it to the end of Y if S_i=1
. - If X and Y have the same number of high elements, S is a good string. Here, the i-th element of a sequence is called high when that element is the largest among the elements from the 1-st to i-th element in the sequence.
Determine if there exists a good string. If it exists, find the lexicographically smallest such string.
Constraints
- 1 \leq N \leq 2 \times 10^5
- 1 \leq P_i \leq N
- P_1,\ P_2,\ ...\ P_N are all distinct.
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
N P_1 P_2 ... P_N
Output
If a good string does not exist, print -1
. If it exists, print the lexicographically smallest such string.
Examples
Input
6 3 1 4 6 2 5
Output
001001
Input
5 1 2 3 4 5
Output
-1
Input
7 1 3 2 5 6 4 7
Output
0001101
Input
30 1 2 6 3 5 7 9 8 11 12 10 13 16 23 15 18 14 24 22 26 19 21 28 17 4 27 29 25 20 30
Output
000000000001100101010010011101
inputFormat
input are integers.
Input
Input is given from Standard Input in the following format:
N P_1 P_2 ... P_N
outputFormat
Output
If a good string does not exist, print -1
. If it exists, print the lexicographically smallest such string.
Examples
Input
6 3 1 4 6 2 5
Output
001001
Input
5 1 2 3 4 5
Output
-1
Input
7 1 3 2 5 6 4 7
Output
0001101
Input
30 1 2 6 3 5 7 9 8 11 12 10 13 16 23 15 18 14 24 22 26 19 21 28 17 4 27 29 25 20 30
Output
000000000001100101010010011101
样例
6
3 1 4 6 2 5
001001