data=input().split()
w=int(data[0])
h=int(data[1])
if data[2]=="W":
    s_1=""
    s_2=""
    for i in range(w):
        if i%2==0:
            s_1+="W"
            s_2+="B"
        else:
            s_1+="B"
            s_2+="W"
    for i in range(h):
        if i%2==0:
            print(s_1)
        else:
            print(s_2)
else:
    s_1=""
    s_2=""
    for i in range(w):
        if i%2==0:
            s_1+="B"
            s_2+="W"
        else:
            s_1+="W"
            s_2+="B"
    for i in range(h):
        if i%2==0:
            print(s_1)
        else:
            print(s_2)