L = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
l = 'abcdefghijklmnopqrstuvwxyz'

s = input()

y = []
for i in range(len(s)):
    if s[i] in L:
        x = L.index(s[i])
        y.append(l[x])
    else:
        x = l.index(s[i])
        y.append(L[x])

print(''.join(y))