Specification: multCenter$($S$,$ i$,$ j$)$ takes a sequence, S$,$ an integer i

# $<=$ len$($S$)$ and an integer j$,$ and returns a new sequence that is

# identical to the sequence S but with the centermost i elements of S

# replicated j times.

#

# Note: "centermost" may not be exact if S is of odd length and i is

# even $($or if S is of even length and i is odd$).$ In such cases,

# "centermost" should shift towards the beginning of the sequence $($see

# first and third examples below$).$

#

# Example:

# $>>>$ multCenter$((1,2,3,4,5,6),1,3)$

# $(1,2,3,3,3,4,5,6)$

# $>>>$ multCenter$((1,2,3,4,5,6),2,2)$

# $(1,2,3,4,3,4,5,6)$

# $>>>$ multCenter$("$abcdefghi$",4,2)$

# 'abcdefcdefghi'

# $>>>$ multCenter$((1,2,3,4,5,6),2,0)$

# $(1,2,5,6)$

What is the speed of the flea?