# 3081 : HQ9+

import numpy as np
from sys import stdin

output=stdin.readline().rstrip('\n')
output=sorted(list(output))
if output[0]!='Q' or output[len(output)-1]!='Q':
    code=-1
elif np.sqrt(len(output)).is_integer():
    code='Q'*int(np.sqrt(len(output)))
else:
    code=-1
print(code)