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

if c=="B":
    for i in range(h):
        if i%2==0:
            print(b)
        else:
            print(a)
else:
    for i in range(h):
        if i%2==0:
            print(a)
        else:
            print(b)