$]$

$[5,6,7,8],$

$[[9,10,11,12]$

for $r$ in range$($len$($numbers$))$:

for $c$ in range$($len$($numbers$[0]))$:

numbers $[r][c]=r+c$

$[1,2,3,4],[5,6,7,8],[9,10,11,12]$

$[0,1,2,3],[1,2,3,4],[2,3,4,5]$

$[1,1,1,1],[5,5,5,5],[9,9,9,9]$

This code will produce an error