# your code goes here
n = int(input())
A = list(map(int, input().split()))
d = int(input())
counter = 0
mp = {}
for k in range(n):
real = A[k] % d
r = d - real
r = r % d
counter += mp.get(r, 0)
for u in range(k):
sum_val = A[u] + A[k]
sum_val = sum_val % d
mp[sum_val] = mp.get(sum_val, 0) + 1
print(counter)
IyB5b3VyIGNvZGUgZ29lcyBoZXJlCm4gPSBpbnQoaW5wdXQoKSkKQSA9IGxpc3QobWFwKGludCwgaW5wdXQoKS5zcGxpdCgpKSkKZCA9IGludChpbnB1dCgpKQpjb3VudGVyID0gMAptcCA9IHt9CmZvciBrIGluIHJhbmdlKG4pOgogICAgcmVhbCA9IEFba10gJSBkCiAgICByID0gZCAtIHJlYWwKICAgIHIgPSByICUgZAogICAgY291bnRlciArPSBtcC5nZXQociwgMCkKICAgIGZvciB1IGluIHJhbmdlKGspOgogICAgICAgIHN1bV92YWwgPSBBW3VdICsgQVtrXQogICAgICAgIHN1bV92YWwgPSBzdW1fdmFsICUgZAogICAgICAgIG1wW3N1bV92YWxdID0gbXAuZ2V0KHN1bV92YWwsIDApICsgMQpwcmludChjb3VudGVyKQ==