Written by Sofiya Vasina
The solution to the cross sum is not quite unique; in
5487961 32 352 39 51 79 58 7986 62 3268 17 4 9 1 79 58 362 32 364 1 5 312 23 249 97 89 4 4 5 86 4..3 23 3125 .. 61 89 62 857 68 9861547
one can replace the two-by-two square of dots above with either
87 78 76 or 85
to obtain a valid solution. In either case, if we "look out for 2 3" as instructed, we find that the 2's and 3's form the following pattern (using # for 2 and 3 and . for all other numbers):
....... ## # # #. .. .. .. .... .# ##.. .. . . . .. .. #.# ## #.. . . #.# ## #.. .. .. . . . .. ...# ## #.#. .. .. .. .# ... .. .......
Interpreting # as "dot" and ## as "dash" and reading each row with #'s in it as a Morse Code letter, this gives us the solution, BAFFLE.