import sys
input = sys.stdin.readline

#N,M = map(int,input().split())
#print(N)

N = int(input())
S = input().rstrip()

if S.count("Q")==1 and \
   "H" not in S and \
   "9" not in S:
	print(S)
elif S.count("Q")==N:
	m = 0
	n = 1
	while m*m < N:
		m += 1
	if m*m==N:
		print("Q"*m)
	else:
		print(-1)
else:
	print(-1)