An Easy Problem!

arr=list('0123456789'+'ABCDEFGHIJKLMNOPQRSTUVWXYZ'+'abcdefghijklmnopqrstuvwxyz')
while 1:
	try:
		a=input()
		if a[0]=='+' or a[0]=='-':
			a=a[1:]
		if a=='0':
			print('2')
		else:
			m=0
			sum=0
			for i in a:
				sum+=arr.index(i)
				if arr.index(i)>m:
					m=arr.index(i)
			ans=0
			for i in range(m,63):
				if sum%i==0:
					ans=i
					break
			if ans==0:
				print('such number is impossible!')
			else:
				print(ans+1)
	except:
		break