## https://yukicoder.me/problems/no/1083

import math

def main():
    N, K = map(int, input().split())
    A = list(map(int, input().split()))
    A.sort()
    answer = -1
    for bit in range(1, 2 ** N, 2):
        k = K
        for i in reversed(range(N)):
            if bit & (1 << i) > 0:
                k = k % A[i]
        answer = max(answer, k)
    print(answer)
        








    



if __name__ == "__main__":
    main()