# The equivalent j is 0 <= J < n
# Explanation
# Fact: Negative integers can be used as indices into
# sequences such as strings
# let s = 'OKEKE'
# i.e n = 5 and let k =-3
# so -5<= -3 <0, since -5 coincides with the first
# member of string s (i.e O) we can conclude 
# that the equivalent of -n on the positive side
# is 0 i.e the LHS of the range is 0 and the
# right hand side is n