s = ''.join(sorted(list(input())))
p = []
for i in range(7):
	if len(s)==1: break
	if s[0]==s[1]: p+=s[0]; s=s[2:]
	else: s=s[1:]+s[0]
if len(s)==1: p+=s
print(s if len(set(p))==7 else "Impossible")