str1 = str(input()) str2 = str1[2:] n = len(str2) dict_str = {'A':10,'B':11,'C':12,'D':13,'E':14,'F':15} a1 = 0 for num in str2: if num in dict_str: a1 = a1 + dict_str[num]*16**(n-1) n = n-1 else: a1 = a1 + int(num)*16**(n-1) n = n-1 print(a1)