import sys
input = sys.stdin.readline
N,B = map(int,input().split())
array = list(map(int,input().split()))

answer = 0
def binarySearch(start,end,target,array):
    global answer
    if start>end:
        return
    
    mid = (start+end)//2
    
    total = 0
    for j in array:
        if j<mid:
            total+=(mid-j)**2
            
    if total<=target:
        answer=mid
        binarySearch(mid+1,end,target,array)
    else:
        binarySearch(start,mid-1,target,array)
        
binarySearch(0,2000000000,B,array)
print(answer)