from collections import deque

N = int(input())
A = list(map(int, input().split()))
que = deque([(0, 0, 0, "")])    # (w, b, i, s)
visited = set()
visited.add((0, 0, 0))         # (w, b, i)

while que:
    if que[0][2] == N:
        # 末端はそのまま、あとで全部調べる
        break
    w,b,i,s = que.popleft()
    a = A[i]
    # 黒に割り当て
    if (w & a) == 0:
        w2, b2, i2, s2 = w, b | a, i + 1, s + "B"
        key = (w2, b2, i2)
        if key not in visited:
            visited.add(key)
            que.append((w2, b2, i2, s2))
    # 白に割り当て
    if (b & a) == 0:
        w2, b2, i2, s2 = w | a, b, i + 1, s + "W"
        key = (w2, b2, i2)
        if key not in visited:
            visited.add(key)
            que.append((w2, b2, i2, s2))

# N個割り当てたものの中で最大値
m = 0
ans = ""
# i==Nのもののみ考慮
for w, b, i, s in que:
    if w * b > m:
        m = w * b
        ans = s
print(m)
print(ans)