def generate_combinations(digits,index,current,result,mapping):
    if index==len(digits):
        result.append(current)
        return 
    for ch in mapping[digits[index]]:
        generate_combinations(digits,index +1, current +ch, result,mapping)
        
digits = input().strip()
if not digits.isdidgits():
    print("Invalid input")
else:
    if  any(d < '2' or d > '9' for d in digits):
        print("Invalid input")
    else:
        mapping = {
            '2': "ABC",
            '3': "DEF",
            '4': "GHI",
            '5': "JKL",
            '6': "MNO",
            '7': "PQRS",
            '8': "TUV",
            '9': "WXYZ"
            
        }
    
        result = []
    
        generate_combinations(digits,0,"",result,mapping)
        print("[",end="")
        print(",".join(result),end="")
        print("]")