#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
   int n,i,k;
   cin>>n>>k;
   int arr[n];
   int rem[k]={0};
   for(i=0;i<n;i++)
   {
       cin>>arr[i];
   }
   for(i=0;i<n;i++)
   {
       rem[arr[i]%k]++;
   }
   int count = 0;
   for(i=1;i<=k/2;i++)
   {
       count = count + max(rem[i],rem[k-i]);
   }
   count = count + (rem[0]>0?1:0);
   if(k%2==0)
   {
     count = count - rem[k/2];
     if(rem[k/2]>0)
        count = count + 1;
   }
   cout<<count;
   return 0;
}