N,K=map(int,input().split())

M=(N+2)//3*3
T=[0]*M
for _ in range(K):
    a,c=input().split()
    a=int(a)
    if c=="R":
        T[a-1]=0
    elif c=="G":
        T[a-1]=1
    else:
        T[a-1]=2

B=[0]*M
for i in range(M//3):
    if T[3*i]==T[3*i+1]:
        B[3*i]=T[3*i]
        B[3*i+1]=(T[3*i]+1)%3
        B[3*i+2]=(T[3*i]+2)%3
    else:
        B[3*i]=T[3*i]
        B[3*i+1]=T[3*i+1]
        B[3*i+2]=3-B[3*i]-B[3*i+1]

B=["RGB"[b] for b in B[:N]]
print(*B,sep="")