count = int(input())
list = input().split()

nums = [i for i in range(count)]
list2 = []
times = []
ans = []
ans_str = []

alp = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']

for i in list:
	remain = int(i)%26
	run = (int(i)-remain)/26
	
	list2.append(remain)
	times.append(run)

while True:
	if list2 == []:
		break
	
	place = times.index(min(times))
	ans.append(list2[place])
	
	list2.pop(place)
	times.pop(place)

for i in ans:
    ans_str.append(alp[i])

ans_str = "".join(ans_str)

print(ans_str)