n,k=map(int,input().split())
ans=[-1]*(n+1)
que=[]
for i in range(k):
    a,k=input().split()
    a=int(a)
    if k=="R":k=0
    elif k=="G":k=1
    else:k=2
    que.append((a,k))
que.sort()
cnt=[0,0,0]
now=1
for a,k in que:
    while now<=3*(a//3):
        for j in range(3):
            if min(cnt)==cnt[j]:
                ans[now]=j
                cnt[j]+=1
                now+=1
                break
    if a%3==0:continue
    elif a%3==1:
        ans[a]=k
        cnt[k]+=1
        now+=1
    else:
        if now==a-1:
            ans[now]=k
            cnt[k]+=1
            now+=1
        else:
            if ans[a-1]==k:continue
            else:
                ans[now]=k
                cnt[k]+=1
                now+=1
res=[]
for i in range(1,n+1):
    if ans[i]==0:
        res.append("R")
    elif ans[i]==1:
        res.append("G")
    else:
        res.append("B")

print("".join(res))