import sys import math import bisect from heapq import heapify, heappop, heappush from collections import deque, defaultdict, Counter from functools import lru_cache from itertools import accumulate, combinations, permutations, product sys.set_int_max_str_digits(10 ** 6) sys.setrecursionlimit(1000000) MOD = 10 ** 9 + 7 MOD99 = 998244353 input = lambda: sys.stdin.readline().strip() NI = lambda: int(input()) NMI = lambda: map(int, input().split()) NLI = lambda: list(NMI()) SI = lambda: input() SMI = lambda: input().split() SLI = lambda: list(SMI()) EI = lambda m: [NLI() for _ in range(m)] def main(): N = NI() ans = 0 for _ in range(N): x = NI() * 10**40 ans += math.isqrt(x) d = ans // 10**20 r = ans - d * 10**20 r //= 10**len(str(d)) print(d, ".", r, sep="") if __name__ == "__main__": main()