import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.Arrays; import java.util.HashMap; import java.util.NoSuchElementException; import java.util.Scanner; public class Main implements Runnable { public static void main(String[] args) throws IOException { new Thread(null, new Main(), "", Runtime.getRuntime().maxMemory()).start(); } long inv(long a) { return pow(a,p-2); } long ADD(long a,long b) { return a+b>=p?a+b-p:a+b; } long SUB(long a,long b) { return ADD(a,p-b); } long[] mul(long[] a, long[] b) { long[] c=new long[a.length+b.length-1]; for (int i=0;i map=new HashMap<>(); for (long a : A) { map.merge(a, 1, Integer::sum); map.merge((M-a)%M, 0, Integer::sum); } long ans=0; for (var e : map.entrySet()) { long pair=(M-e.getKey())%M; if (pair != e.getKey()) { if (e.getValue() < map.get(pair) || (e.getValue()==map.get(pair) && e.getKey() < pair)) continue; } ans+=e.getValue(); } System.out.println(ans); } static void tr(Object... objects) { System.out.println(Arrays.deepToString(objects)); } } class FastScanner { private final InputStream in = System.in; private final byte[] buffer = new byte[1024]; private int ptr = 0; private int buflen = 0; private boolean hasNextByte() { if (ptr < buflen) { return true; } else { ptr = 0; try { buflen = in.read(buffer); } catch (IOException e) { e.printStackTrace(); } if (buflen <= 0) { return false; } } return true; } private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1; } private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126; } private void skipUnprintable() { while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; } public boolean hasNext() { skipUnprintable(); return hasNextByte(); } public String next() { if (!hasNext()) throw new NoSuchElementException(); StringBuilder sb = new StringBuilder(); int b = readByte(); while (isPrintableChar(b)) { sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } public long nextLong() { if (!hasNext()) throw new NoSuchElementException(); long n = 0; boolean minus = false; int b = readByte(); if (b == '-') { minus = true; b = readByte(); } if (b < '0' || '9' < b) { throw new NumberFormatException(); } while (true) { if ('0' <= b && b <= '9') { n *= 10; n += b - '0'; } else if (b == -1 || !isPrintableChar(b)) { return minus ? -n : n; } else { throw new NumberFormatException(); } b = readByte(); } } public int nextInt() { return (int) nextLong(); } }