n = int(input())
S = input()
for s in S:
    if s == "9" or s == "H":
        print(-1)
        exit()
q = S.count("Q")
if q == 0:
    print(-1)
    exit()
for i in range(10**3):
    if i*i == q:
        break
else:
    print(-1)
    exit()
if n%i:
    print(-1)
    exit()
m = n//i
P = S[:m]
if P.count("Q") != i:
    print(-1)
    exit()
if S == P*i:
    print(P)
else:
    print(-1)