#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cmath>
#include <tuple>
#include <bitset>

#define rep(i,n) for(i=0; i<n; ++i)
#define in(a) cin >> a
#define out(a,b) cout << a << b
using namespace std;
using lint = long long;

int main(void){
    lint i, j;
    lint n, m;
    in(n);
    in(m);
    vector<lint> rem(m/2+m%2,0);
    vector<lint> REM(m/2,0);
    rep(i,n){
        lint num;
        in(num);
        if((num%m)>=(m/2+m%2)){
            REM[(num%m)-(m/2+m%2)]++;
        }
        else{
            rem[num%m]++;
        }
        
    }
    lint cnt=0;
    if(rem[0]!=0)   cnt++;
    for(i=1; i<(m/2); ++i){
        lint elem=max(rem[i],REM[m/2-i]);
        cnt+=elem;
    }
    if(m%2==0&&REM[0]!=0) cnt++;
    else if(m%2==1) cnt+=max(rem[m/2],REM[0]);
    if(cnt<1)   cnt=1;
    out(cnt,endl);

    return 0;
}