package main

import (
    "fmt"
)

func main() {
    var (
        h	int
        w	int
        c	string
        cc	string
    )
    fmt.Scan(&w)
    fmt.Scan(&h)
    fmt.Scan(&c)
    
    if c == "W" {
        cc = "B"
    } else {
        cc = "W"
    }
    
    for y := 0; y < h; y++ {
        for x := 0; x < w; x++ {
            if(y % 2 == x % 2) {
                fmt.Print(c)
            } else {
                fmt.Print(cc)
            }
            
        }
        
        fmt.Println("")
    }
}