Notice the distribution, you can never see more than three repeating a in the same word, could it be roman numerals ? The only letters used are A, E, & J. Converting them to numbers A=1, E=5, J=10 then to roman numerals, A=I, E=V and J=X

vii vii vii v viii iii v v v vii vii ix viii v viii iv viii iii vii iii vi viii vi ix v iii v v v 0 vii iv vi i ix

Convert roman numerals to decimal

7 7 7 5 8 3 5 5 5 7 7 9 8 5 8 4 8 3 7 3 6 8 6 9 5 3 5 5 5 0 7 4 7 9

Make pairs

77 75 83 55 57 79 85 84 83 73 68 69 53 55 50 74 79

Convert decimal to Ascii

MKS79OUTSIDE572JO

Rot +1 will give you

ppo47simple275ju

Notice that some letters are capitals? Let’s split every unbounded words then count the position where the capital letter is

Make pairs with the numbers

89 84 74 56 50 53 57 50 78 82

Convert decimal to Ascii

YTJ82592NR

We now have the prefix and suffix, obviously the keyword is unbounded

ytj82unbounded592nr