# Arup Guha
# 10/11/2021
# Solution to 2021 UCF Locals Problem: Odd/Even Strings

# read string.
inp = input("")

# frequency array
freq = [0]*26

# Add 1 to the frequency of each letter.
for let in inp:
    freq[ord(let)-ord('a')] += 1

# Initially these are both true.
even = True
odd = True

# Go through each frequency.
for i in range(len(freq)):

    # These don't count.
    if freq[i] == 0:
        continue
    
    # One or the other is false each time.
    if freq[i]%2 == 0:
        odd = False
    else:
        even = False

# Print accordingly.
if even:
    print("0")
elif odd:
    print("1")
else:
    print("0/1")