import sys, random
input = lambda : sys.stdin.readline().rstrip()


write = lambda x: sys.stdout.write(x+"\n"); writef = lambda x: print("{:.12f}".format(x))
debug = lambda x: sys.stderr.write(x+"\n")
YES="Yes"; NO="No"; pans = lambda v: print(YES if v else NO); INF=10**18
LI = lambda : list(map(int, input().split())); II=lambda : int(input())
def debug(_l_):
    for s in _l_.split():
        print(f"{s}={eval(s)}", end=" ")
    print()
def dlist(*l, fill=0):
    if len(l)==1:
        return [fill]*l[0]
    ll = l[1:]
    return [dlist(*ll, fill=fill) for _ in range(l[0])]

n,k = list(map(int, input().split()))
ans = [0]*(n+3)
tmp = [[] for _ in range(n+3)]
for i in range(k):
    a,c = input().split()
    a = int(a)
    a -= 1
    d,m = divmod(a,3)
    for ind in range(3*d, 3*d+3):
        if c in tmp[ind]:
            break
    else:
        ans[a] = c
        for ind in range(3*d, 3*d+3):
            tmp[ind].append(c)
#     print(tmp, c)
for i in range((n+2)//3):
    s = set("RGB")
    for j in range(3*i, 3*i+3):
        if ans[j]!=0:
            s.remove(ans[j])
    for j in range(3*i, 3*i+3):
        if ans[j]==0:
            ans[j] = s.pop()
count = {}
for c in "RGB":
    count[c] = 0
for i in range(n):
    assert ans[i] in "RGB"
    count[ans[i]] += 1
    assert count[ans[i]]==max(count.values())
write("".join(ans[:n]))