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)

results = []   # N個割り当てたものを保存

while que:
    w, b, i, s = que.popleft()
    if i == N:
        results.append((w, b, s))
        continue
    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 = ""
for w, b, s in results:
    if w * b > m:
        m = w * b
        ans = s
print(m)
print(ans)