n, k = map(int, input().split())
info = [list(input().split()) for _ in range(k)]


for i in range(k):
    info[i] = (int(info[i][0]), info[i][1])

info.sort()


ans = ['R', 'G', 'B'] * n
for cnt, color in info:
    cnt -= 1
    if cnt % 3 == 0:
        if ans[cnt] == color:
            continue
        else:
            for i in range(1, 3):
                if ans[cnt + i] == color:
                    ans[cnt], ans[cnt + i] = ans[cnt + i], ans[cnt]

    if cnt % 3 == 1:
        if ans[cnt - 1] == color or ans[cnt] == color:
            continue
        else:
            ans[cnt], ans[cnt + 1] = ans[cnt + 1], ans[cnt]
    if cnt % 3 == 2:
        continue

print(''.join(ans[:n]))