Q: Is C a great language, or what? Where else could you write something like a+++++b ?
A: Well, you can't meaningfully write it in C, either. The rule for lexical analysis is that at each point during a straightforward left-to-right scan, the longest possible token is determined, without regard to whether the resulting sequence of tokens makes sense. The fragment in the question is therefore interpreted as
a ++ ++ + band cannot be parsed as a valid expression.
K&R1 Sec. A2 p. 179
K&R2 Sec. A2.1 p. 192
ISO Sec. 6.1
H&S Sec. 2.3 pp. 19-20