Preprocessor follows greedy approach to tokenize, This can be done in TWO steps
1 => Separated by space (A+ ++B) => Have 4 tokens(Space is not considered as token), here tokens are A, +, ++, B(In order of expression). If any operator doesn't have any space ,
then ,
2 => Greedy approach (A+++B) for longest possible valid operator in the Grammer => Like we have '++' > '+' so here the tokens are A,++, +, B(In order of expression).