The parser must implement an order of precedence of left to right, brackets are used to explicitly denote precedence by grouping parts of an expression that should be evaluated first again left to right

The parser must recognise the input string and evaluate the expression.

Rules:

a = '+', b = '-', c = '*', d = '/', e = '(', f = ')'

Input: 3a2c4
Result: 20

Input: 32a2d2
Result: 17

Input: 500a10b66c32
Result: 14208

Input: 3ae4c66fb32
Result: 235

Input: 3c4d2aee2a4c41fc4f
Result: 990

Written in C# with NUnit and SpecFlow tests.