s=input()
s1=""
for i in s:
    if i>="A" and i<="Z":
        s1=s1+i.lower()
    elif i>="a" and i<="z":
        s1=s1+i.upper()
    else:
        s1=s1+i
print(s1)
/**************************************************************
	Problem: 1182
	User: admin
	Language: Python
	Result: Accepted
	Time:92 ms
	Memory:34244 kb
****************************************************************/