n,t=map(int,input().split())
a=list(map(int,input().split()))
b=[]
for i in range(0,len(a)-2):
for j in range(i+1,len(a)-1):
for x in range(j+1,len(a)):
s=(a[i]+a[j]+a[x])//3
if s<t: b.append(t-s) if s>t:
b.append(s-t)
print(min(b))