Kr, Kb = gets.split.take(2).map(&:to_i)
S = gets.chomp

def ng_at(s, i)
  r = []
  range = 0...s.size
  !case s[i]
  when ?R
    r << i - Kr if range.cover?(i - Kr) && s[i - Kr] == ?R
    r << i + Kr if range.cover?(i + Kr) && s[i + Kr] == ?R
  when ?B
    r << i - Kb if range.cover?(i - Kb) && s[i - Kb] == ?B
    r << i + Kb if range.cover?(i + Kb) && s[i + Kb] == ?B
  else
  end
  r
end

def valid?(s)
  !s.size.times.any?{|i|
    !ng_at(s, i).empty?
  }
end

def count_ng(s)
  count = 0
  s.size.times{|i|
    count += ng_at(s, i).size
  }
  count
end

q = [S]
while !q.empty?
  s = q.shift
  S.size.times{|i|
    ngs = ng_at(s, i)
    ngs.each{|ng_idx|
      t = s[0...ng_idx] + s[ng_idx..-1]
      if valid?(t)
        p t
        exit
      end
      q << t if !q.include?(t)
    }
  }
end