def max_power_7_le_k(K):
    if K < 1:
        return -1
    low = 0
    high = 1
    while 7 ** high <= K:
        high *= 2
    while low <= high:
        mid = (low + high) // 2
        try:
            val = 7 ** mid
        except OverflowError:
            val = float('inf')
        if val == K:
            return mid
        elif val < K:
            low = mid + 1
        else:
            high = mid - 1
    return high

def find_char(N, K):
    current_level = N
    current_K = K
    while True:
        for c in ['y', 'u', 'u', 's', 'a', 'a', 'n']:
            if c in ('u', 'a'):
                m = max_power_7_le_k(current_K)
                if m >= current_level - 1:
                    len_c = 7 ** (current_level - 1)
                    if current_K <= len_c:
                        if current_level == 1:
                            return c
                        current_level -= 1
                        replace_str = ['y', 'u', 'u', 's', 'a', 'a', 'n']
                        current_string = replace_str
                        break
                    else:
                        current_K -= len_c
                else:
                    continue
            else:
                len_c = 1
                if current_K <= len_c:
                    return c
                else:
                    current_K -= len_c
        else:
            if current_level == 1:
                return current_string[current_K - 1]
            else:
                current_level -= 1
                current_string = ['y', 'u', 'u', 's', 'a', 'a', 'n']

def main():
    import sys
    input = sys.stdin.read().split()
    N = int(input[0])
    K = int(input[1])
    print(find_char(N, K))

if __name__ == "__main__":
    main()