def reverse_word_in_string(s: str, word: str) -> str:
pos = s.find(word)
if pos != -1:
reversed_word = word[::-1]
s = s[:pos] + reversed_word + s[pos + len(word):]
return s
text = "C++ C Java Python PHP C#"
target = "Java"
result = reverse_word_in_string(text, target)
print(result)
'''
run:
C++ C avaJ Python PHP C#
'''