#!/usr/bin/env python3

from math import floor

n = int(input())
xs = list(map(int, input().split()))

# list of (sum_x, count)
# center = sum_x/count
intervals = []


def overlap(l, r):
    # TODO: Convert to integer logic?
    return l[0] / l[1] + l[1] / 2 >= r[0] / r[1] - r[1] / 2


def merge(l, r):
    return (l[0] + r[0], l[1] + r[1])


for x in xs:
    intervals.append((x, 1))

    # print(intervals)
    # NOTE: WA because this `if` should be `while`.
    if len(intervals) >= 2 and overlap(intervals[-2], intervals[-1]):
        intervals[-2] = merge(intervals[-2], intervals[-1])
        intervals.pop()
    # print(intervals)

# Convert intervals to actual position ranges
for i in range(len(intervals)):
    (s, cnt) = intervals[i]

    if cnt % 2 == 0:
        # the middle is a half integer
        # round s to a half integer (x.5)
        m = floor(s / cnt)
        l = m - cnt // 2 + 1
        r = m + cnt // 2
    else:
        # the middle is integer
        m = round(s / cnt)
        l = m - (cnt - 1) // 2
        r = m + (cnt - 1) // 2

    # print(l, r)
    intervals[i] = [l, r]

ans = 0
i = 0
for x in xs:
    ans += (x - intervals[i][0]) ** 2
    intervals[i][0] += 1
    if intervals[i][0] > intervals[i][1]:
        i += 1
print(ans)