BEBRAS 2017 Grade 5-6 Round 2 Ext Question 7

Bebras City has installed an electronic noticeboard. Beaver is asked to write a program to send information to it and is excited by the interesting task. In computing, a symbol may have several meanings. We know + means addition in mathematics, as in 6 + 3 = 9, but in computing it may join pieces of text.

For example:

"10:47" + " " + "BEAVER FALLS" + " - " + "PLATFORM" + " " + "3"

displays:

"10:47 BEAVER FALLS - PLATFORM 3"

This looks simple, but using a symbol with several meanings in one expression can be confusing. How is this expression interpreted?

"7 + 8" + " + " + "1 + " + "2" + "5"