dic = {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9, 'A': 10, 'B': 11, 'C': 12,
       'D': 13, 'E': 14, 'F': 15, 'G': 16, 'H': 17, 'I': 18, 'J': 19, 'K': 20, 'L': 21, 'M': 22, 'N': 23, 'O': 24,
       'P': 25, 'Q': 26, 'R': 27, 'S': 28, 'T': 29, 'U': 30, 'V': 31, 'W': 32, 'X': 33, 'Y': 34, 'Z': 35}


def convert(num: str, x: int, reverse=False):
    if not reverse:
        s = 0
        for i in num.upper():
            s = s * x + dic.get(i)
        return s
    else:
        num = int(num)
        lis = list(dic)
        ls = ""
        while num > 0:
            ls += lis[num % x]
            num //= x
        return ls[::-1]


if __name__ == '__main__':
    n = int(input())
    a = input()
    b = input()
    print(convert(str(convert(a, n) + convert(b, n)), n, reverse=True))