deffinitely
->
definitely
(used twice in statement)

Also I suggest the following change:
The first line contains the length of the row L and the number of groups of consecutive cells that must be painted (1 ≤ L ≤ 400). The second line contains K integers (0 ≤ K ≤ L), which are the lengths of these groups.
->
The first line contains the length of the row L (1 ≤ L ≤ 400) and the number of groups of consecutive cells that must be painted K (0 ≤ K ≤ L). The second line contains K integers, which are the lengths of these groups.