W,H,C = map(str,input().split())
W = int(W)
H = int(H)
b = ""
for i in range(W) :
    if i % 2 == 0 :
        b += "B"
    else :
        b += "W"

w = ""
for i in range(W) :
    if i % 2 == 0 :
        w += "W"
    else :
        w += "B"


ans = []

if C == "B" :
    for i in range(H) :
        if i % 2 == 0 :
            ans.append(b)
        else :
            ans.append(w)
else :
    for i in range(H) :
        if i % 2 == 0 :
            ans.append(w)
        else :
            ans.append(b)
print(*ans,sep="\n")