a=input().split()
c="B" if a[2]=="W" else "W"
s=""
for i in range(0, int(a[0])): s+=a[2] if i%2==0 else c
ss=s[1:]+ ("B" if s[-1]=="W" else "W")
for i in range(0, int(a[1])): print(s if i%2==0 else ss)