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#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include <bits/stdc++.h>
#include "message.h"
#include "teatr.h"

using namespace std;
#define PB push_back
#define MP make_pair
#define LL long long
//#define int LL
#define FOR(i,a,b) for(int i = (a); i <= (b); i++)
#define RE(i,n) FOR(i,1,n)
#define REP(i,n) FOR(i,0,(int)(n)-1)
#define VI vector<int>
#define PII pair<int,int>
#define LD double
#define FI first
#define SE second
#define st FI
#define nd SE
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())

template<class C> void mini(C &a4, C b4) { a4 = min(a4, b4); }
template<class C> void maxi(C &a4, C b4) { a4 = max(a4, b4); }

template<class TH> void _dbg(const char *sdbg, TH h){ cerr<<sdbg<<'='<<h<<endl; }
template<class TH, class... TA> void _dbg(const char *sdbg, TH h, TA... a) {
  while(*sdbg!=',')cerr<<*sdbg++;
  cerr<<'='<<h<<','; _dbg(sdbg+1, a...);
}

template<class T> ostream &operator<<(ostream& os, vector<T> V) {
  os << "["; for (auto vv : V) os << vv << ","; return os << "]";
}
template<class L, class R> ostream &operator<<(ostream &os, pair<L,R> P) {
  return os << "(" << P.st << "," << P.nd << ")";
}

#ifdef LOCAL
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (__VA_ARGS__)
#define cerr if(0)cout
#endif

const int MaxSize = 1 << 20;

int ptree[MaxSize];
int val_prefs[MaxSize];

void IncTree(int val) {
  while (val) {
    ++ptree[val];
    val -= val & (-val);
  }
}

int SumSuf(int start) {
  int ans = 0;
  while (start < MaxSize) {
    ans += ptree[start];
    start += start & (-start);
  }
  return ans;
}

int my_node;
int num_nodes;
int N;
vector<int> intv_starts;

int32_t main() {
  my_node = MyNodeId();
  num_nodes = NumberOfNodes();

  if (num_nodes % 2 == 0) {
    --num_nodes;
    if (my_node >= num_nodes) { return 0; }
  }

  N = GetN();
  for (int i = 0; i <= num_nodes; ++i) {
    intv_starts.push_back((LL)N * i / num_nodes);
  }

  LL cur_inversions = 0;
  for (int i = intv_starts[my_node]; i < intv_starts[my_node + 1]; ++i) {
    const int val = GetElement(i);
    cur_inversions += SumSuf(val + 1);
    IncTree(val);
    ++val_prefs[val];
  }

  debug(intv_starts);

  const int intv_size = intv_starts[my_node + 1] - intv_starts[my_node];

  for (int i = 1; i < MaxSize; ++i)
    val_prefs[i] += val_prefs[i - 1];

  const int num_next_nodes = (num_nodes - 1) / 2;
  for (int node_incr = 1; node_incr <= num_next_nodes; ++node_incr) {
    const int node_pos = (my_node + node_incr) % num_nodes;
    const int from = intv_starts[node_pos];
    const int to = intv_starts[node_pos + 1];

    if (node_pos > my_node) {
      for (int i = from; i < to; ++i) {
        const int val = GetElement(i);
        cur_inversions += intv_size - val_prefs[val];
      }
    } else {
      for (int i = from; i < to; ++i) {
        const int val = GetElement(i);
        cur_inversions += val_prefs[val - 1];
      }
    }
  }

  debug(cur_inversions);

  PutLL(0, cur_inversions);
  Send(0);
  if (my_node) { return 0; }

  LL answer = 0;

  for (int i = 0; i < num_nodes; ++i) {
    Receive(i);
    answer += GetLL(i);
  }

  cout << answer << "\n";
}