N, K = map(int, input().split())
AC = []
for _ in range(K):
    a, c = input().split()
    AC.append((int(a), c))
AC = dict(AC)
ans = []
dic = {"R": 0, "G": 1, "B": 2}
color = ["R", "G", "B"]
X = [0, 0, 0]
for i in range(-(-N // 3)):
    tmp = []
    k = 0
    for j in range(3):
        cnt = 3 * i + j + 1
        if cnt in AC and AC[cnt] not in tmp:
            c = AC[cnt]
            tmp.append(c)
            k = (dic[c] + 1) % 3
        else:
            while color[k] in tmp:
                k = (k + 1) % 3
            tmp.append(color[k])
    ans += tmp
ans = ans[:N]
print("".join(ans))