{}
def check(colours):
c=[]
for i in colours:
c.append(i)
for i in range (1,len(c)+1):
for j in range (i,len(c)+1):
x = i + j
if x < len(c)+1:
if c[x-1] == c[i-1] and c[x-1] == c[j-1]:
return False
return True
arr=["R","G","B"]
sol=[]
for i in range(1,15):
for j in range(len(arr)**i):
ret=""
new=j
for _ in range(i):
ret+=arr[new%len(arr)]
new/=len(arr)
new=int(new)
if check(ret):
print("n="+str(i))
print(ret)
break