let i = require('fs').readFileSync('/dev/stdin', 'utf8').split('\n')[0].split(' ')
let a = i[0] % 2
let wb = (new Array((i[0] - a) / 2)).fill('WB').join('') + (a == 1 ? 'W' : '')
let bw = 'B' + wb.slice(0, -1)
let f,s
if (i[2] === 'W') {
  f = wb
  s = bw
} else {
  f = bw
  s = wb
}
for (let c = 0; c < i[1]; c++) {
  console.log(c % 2 == 0 ? f : s)
}