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Problem Statement

We have an integer sequence of length $N$ stored in our server. Until just a minute ago, this sequence contained one occurrence of each integer from $1$ to $N$.

However, trouble has occurred, which may have replaced one element in the sequence with another integer between $1$ and $N$ (inclusive). It is also possible that there was no such overwrite.

Given is the integer sequence after the trouble, $A_1, \ldots, A_N$. Write a program that reads it and determines whether there was an overwrite. If there was an overwrite, the program should also report which integer was replaced with which integer.

Constraints

• $1 \leq N \leq 200000$
• $1 \leq A_i \leq N$
• The sequence $A_1, \ldots, A_N$ is consistent with the situation described in Problem Statement.

Sample Input 1Copy

6
1
5
6
3
2
6

Sample Output 1Copy

6 4

The original sequence should have contained one occurrence of each integer from $1$ to $6$. However, the given sequence contains two occurrences of $6$ and no occurrence of $4$. Thus, we can see that $4$ was replaced with $6$.

Sample Input 2Copy

7
5
4
3
2
7
6
1

Sample Output 2Copy

Correct

The original sequence should have contained one occurrence of each integer from $1$ to $7$, and so does the given sequence. Thus, we can see that there was no overwrite.