#def function
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def fun(s):
k=len(s)
m=' '
for i in range(0,k):
if s[i].isupper():
m=m+s[i].lower()
elif s[i].isalpha():
m=m+s[i].upper()
else:
if s[i].isdigit():
m=m+ 'll'
else:
if s[i].isspace():
m=m + 'e'
else:
m=m + 'i'
print(m)
fun('rag kI2sbra$n')
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#Output:
' RAGeKillSBRAiN '