import std.stdio;
import std.string;
import std.conv;
import std.range;

//-------------------------

void main(){
  auto line = readln.chomp.split(" ");
  int width  = line[0].to!int;
  int height = line[1].to!int;
  auto design = "BW".cycle;
  auto start = (line[2] == "B") ? 0 : 1;

  foreach(i; 0..height){
    writeln(design.take(width + 1).array[start..start + width]);
    start = start^1;
  }
}