local n, k = io.read("*n", "*n", "*l")
local m = {}
m.R, m.G, m.B = 1, 2, 3
local t = {}
for i = 1, n + 3 do t[i] = 0 end
for i = 1, k do
  local pos, val = io.read():match("(%d+) (%w)")
  pos = tonumber(pos)
  val = m[val]
  t[pos] = val
end

local ret = {}
for i = 1, n, 3 do
  if t[i] == 1 then
    table.insert(ret, "R")
    if t[i + 1] == 3 then
      table.insert(ret, "B")
      table.insert(ret, "G")
    else
      table.insert(ret, "G")
      table.insert(ret, "B")
    end
  elseif t[i] == 2 then
    table.insert(ret, "G")
    if t[i + 1] == 3 then
      table.insert(ret, "B")
      table.insert(ret, "R")
    else
      table.insert(ret, "R")
      table.insert(ret, "B")
    end
  else
    table.insert(ret, "B")
    if t[i + 1] == 1 then
      table.insert(ret, "R")
      table.insert(ret, "G")
    else
      table.insert(ret, "G")
      table.insert(ret, "R")
    end
  end
end
for i = n + 1, #ret do
  table.remove(ret)
end
print(table.concat(ret))