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2106. Prime Number with Prime Frequency

You are given an array of n numbers, find any prime number that appears a prime number of times in the array.

Input

The first line contains an integer n(1≤n≤106).

The second line contains the numbers given separated by spaces, ai(1≤ai≤106).

Output

Output the solution on a single line. If there are multiple answers, output any of them. If there is no solution, output −1.

Sample input 1

4
1 2 2 3

Sample output 1

2

Sample input 2

5
1 2 2 2 2

Sample output 2

-1

Sample input 3

5
1 1 1 2 2

Sample output 3

2

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Problem
ARidwan 91
BTimosh and Marathon 80
CSum of KEPpy Numbers 72
DPrime Number with Prime Frequency 65
E1Asilbek and Configurations #1 37
E2Asilbek and Configurations #2 35
F1Timosh and Subarrays #1 26
F2Timosh and Subarrays #2 20
G1Timosh and Number Theory #1 5
G2Timosh and Number Theory #2 2
H1Bamboo Tablet Archive #1 17
H2Bamboo Tablet Archive #2 13
H3Bamboo Tablet Archive #3 3
MediumData structuresBruteforce
83 / 10
Solved / unsolved count
2.0 s / 256 MB
Limits
LanguageSpecific limits
Python 3.124.0 s / - MB