text = input().upper()

unique_symbols = ""
current_symbol = ""
repetitions = ""

for i in range(len(text)):
    if not text[i].isdigit():
        current_symbol += text[i]

    else:
        for idx in range(i, len(text)):
            if not text[idx].isdigit():
                break
            repetitions += text[idx]
        repetitions = int(repetitions)
        unique_symbols += repetitions * current_symbol
        current_symbol = ""
        repetitions = ""

print(f"Unique symbols used: {len(set(unique_symbols))}")
print(unique_symbols)