715 B | 715 chars
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
sys.setrecursionlimit(10**7)
BLANK = " "
# inp = input
inp = lambda : sys.stdin.readline().rstrip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
n, m = mii()
l = mii()
d = {}
i = 1
while i * i <= m:
if m % i == 0:
d[i] = 1
d[m // i] = 1
i+= 1
cnt = 0
for i in l:
crt = i
while d.get(crt + 1, False):
crt += 1
cnt += 1
p(cnt)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()