How to create List A of two Min. lists B with heterogeneous length in R?

I am trying to create a minimum list of two lists in R based on the thread How to make a great R reproducible example? but it does not cover the list of lists as a basic example. Wanted minimum data sample of the following structure where B length can be minimised but must be heterogeneous

List of 2
 $ :'data.frame':   541650 obs. of  2 variables:
  ..$ V1: num [1:541650] -0.21 -0.205 -0.225 -0.22 -0.21 -0.19 -0.205 -0.205 -0.205 -0.205 ...
  ..$ V2: num [1:541650] -0.245 -0.22 -0.2 -0.2 -0.195 -0.2 -0.19 -0.185 -0.18 -0.185 ...
 $ :'data.frame':   426098 obs. of  2 variables:
  ..$ V1: num [1:426098] -0.285 -0.285 -0.185 -0.285 -0.385 -0.305 -0.305 -0.125 -0.015 -0.285 ...
  ..$ V2: num [1:426098] -0.445 -0.6 -0.815 -0.665 -0.49 -0.68 -0.555 -0.755 -0.795 -0.405 ...

Doing dput(files), you get too big example data. Doing reproduce(files), the same case. I also tried dput(head(files, 5)) but to one list and returns then only 5 digits. Pseudocode

• structure List A of two lists B(1,2) where the length of B(1,2) varies such that

  length(B(1)_i) = length(B(2)_i) 
  
  

• minimise length of B(1,2) but keep heterogeneous length of subsequent Bs

R: 3.3.1
OS: Debian 8.5