n,d,k,*x=$<.read.split.map &:to_i
y=(0..n-d).map{|i|(i+1..i+d).map{|j|[x[j]-x[i],-i,-j]}.max}.max
if y[0]<1
 p 0
else
 p y[0]*k
 print y[2],' ',y[1]
end