w,h,c=input().split()

w=int(w)
h=int(h)

a=[[0 for j in range(w)] for i in range(h)]

a[0][0]=c
for i in range(1,h):
    if a[i-1][0]=='B':
        a[i][0]='W'
    else:
        a[i][0]='B'

for i in range(h):
    for j in range(1,w):
        if a[i][j-1]=='B':
            a[i][j]='W'
        else:
            a[i][j]='B'
    
for g in a:
    print(''.join(g))