score_list=[65, 92, 78, 90, 45, 83, 57, 96]
score_dict={'high':[],'middle':[],'low':[]}
for score in score_list :
 if score >=90:
   score_dict['high'].append(score)
 elif score >=60:
  score_dict['middle'].append(score)
 else:
  score_dict['low'].append(score)
print(score_dict)