n,d,K,*x=$<.read.split.map &:to_i
m=[0,0,0]
c=h=x[0]+1
n.times{|j|f=[j+d,n-1].min
x[j]>=c&&x[f]<x[h]&&next
(j+1..f).map{|k|v=x[k]-x[j]
v<0&&break
v>m[0]&&m=[v,j,k]}
h=f
c=x[j]}
m[0]<1?p(0):puts(m[0]*K,m[1,2]*' ')