Given $n$ , create two permutations $a$ and $b$ of size $n$ such that $a_i+b_i$ is prime for $i=1,2,\dots,n$ .
The only line has an integer $n$ .
Print two permutations. You can print any valid solution. If there are no solutions, print IMPOSSIBLE .
5\n
2 1 3 5 4 5 1 4 2 3· · · · \n · · · · \n
The sums are $2+5=7$ , $1+1=2$ , $3+4=7$ , $5+2=7$ and $4+3=7$ which all are primes.