N,K=map(int,input().split())
ans=0
import itertools

A=list(map(int,input().split()))
list(itertools.permutations(A))
for a in list(itertools.permutations(A)):
       c=K
       for i in range(N):
           c=c%a[i]
       ans=max(c,ans)
print(ans)