c# - Using a regular expression to find words with lower and upper case characters in parenthesis -

i'm creating program searches string finding words in parenthesis lower , upper case characters can't seem figure out regular expression use. example word - (lowerupper)

regular expression :

string upperlowerparens = "\\([a-z][a-z][a-z]+[a-z]+\\)"; 

try 1

\(([a-z]+[a-z]+)[a-za-z]*\)|\(([a-z]+[a-z]+[a-za-z]*)\) 

• explanation

this divided 2 parts if 1 of them matched word between brackets matched

1. \(([a-z]+[a-z]+)[a-za-z]*\) validates (lowerupper) capital letters appears first
2. \(([a-z]+[a-z]+[a-za-z]*)\) validates (upperlower) lower case letters appears first

f want allow spaces after , before brackets can change regex \( *([a-z]+[a-z]+)[a-za-z]* *\)|\( *([a-z]+[a-z]+[a-za-z]*) *\)

check demo here demo