import sys
#input = sys.stdin.readline
input = sys.stdin.buffer.readline #文字列はダメ
#sys.setrecursionlimit(1000000)
#import bisect
#import itertools
#import random
#from heapq import heapify, heappop, heappush
from collections import defaultdict 
#from collections import deque
#import copy
#import math
#from functools import lru_cache
#@lru_cache(maxsize=None)
#MOD = pow(10,9) + 7
#MOD = 998244353
#dx = [1,0,-1,0]
#dy = [0,1,0,-1]
#dx8 = [1,1,0,-1,-1,-1,0,1]
#dy8 = [0,1,1,1,0,-1,-1,-1]

def main():
    N,M = map(int,input().split())
    A = list(map(int,input().split()))

    dic = defaultdict(int)
    for a in A:
        dic[a%M] += 1
    
    ans = 0
    if M%2 == 0:
        ans += min(1, dic[0])
        for i in range(1,M//2):
            ans += max(dic[i], dic[M-i])
        ans += min(1, dic[M//2])
    else:
        ans += min(1, dic[0])
        for i in range(1,(M+1)//2):
            ans += max(dic[i], dic[M-i])

    print(ans)

if __name__ == '__main__':
    main()