Questão F

https://codeforces.com/group/Ly2TbDDpGd/contest/253504/problem/F

n = int(input())
x = (input())
second = x.split()
second = list(map(int, second))
for i in second:
    second.remove(i)
    while True:
        if i in second and i >= 1:
            i -= 1
            continue
        break
    second.append(i)


print(sum(second))