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#include<cstdio>
#include "message.h"
#include "teatr.h"

int M = 1000000;
int start;
int end;
int number_of_nodes;
int node_id;

int * t;
int * counts;
int * prev_counts;
int * tmp;
int biggest = 0;
int prev_biggest = 0;

long long local_result = 0;

int min(int a, int b) {
  return a > b ? b : a;
}

int max(int a, int b) {
  return a > b ? a : b;
}

void init() {
  node_id = MyNodeId();
  number_of_nodes = NumberOfNodes();
  int n = GetN();
  start = min(node_id * M, n);
  end = min((node_id + 1) * M, n);
  counts = new int[M + 5];
  prev_counts = new int[M + 5];
  t = new int[M + 5];
  tmp = new int[M + 5];
  for (int i = 0; i < M + 5; i++) {
    counts[i] = 0;
    prev_counts[i] = 0;
  }
  for (int i = start; i < end; i++) {
    t[i - start] = GetElement(i);
  }
}

long long merge(int left, int mid, int right) {
  long long inversions = 0;
  int i = left;
  int j = mid;
  int k = left;

  while((i <= mid - 1) && (j <= right)) {
    if (t[i] <= t[j]) {
      tmp[k++] = t[i++];
    } else {
      tmp[k++] = t[j++];
      inversions += (mid - i);
    }
  }

  while(i <= mid - 1) {
    tmp[k++] = t[i++];
  }

  while(j <= right) {
    tmp[k++] = t[j++];
  }

  for (int i = left; i <= right; i++) {
    t[i] = tmp[i];
  }

  return inversions;
}

long long merge_sort(int left, int right) {
  int mid;
  long long inversions = 0;
  if (right > left) {
    mid = (right + left) / 2;
    inversions += merge_sort(left, mid);
    inversions += merge_sort(mid + 1, right);
    inversions += merge(left, mid + 1, right);
  }
  return inversions;
}

long long count_inversions() {
  if (end == start) {
    return 0;
  }
  return merge_sort(0, end - start - 1);
}

void compute_local() {
  local_result = count_inversions();
}

void count() {
  for (int i = start; i < end; i++) {
    int next = t[i - start];
    counts[next]++;
    biggest = max(biggest, next);
  }
}

void receive_counts() {
  if (node_id != 0) {
    Receive(node_id - 1);
    prev_biggest = GetInt(node_id - 1);
    for (int i = 0; i < prev_biggest; i++) {
      prev_counts[i] = GetInt(node_id - 1);
    }
    biggest = max(biggest, prev_biggest);
  }
}

void send_counts() {
  if (node_id != number_of_nodes - 1) {
    PutInt(node_id + 1, biggest + 1);
    for (int i = 0; i <= biggest; i++) {
      PutInt(node_id + 1, counts[i] + prev_counts[i]);
    }
    Send(node_id + 1);
  }
}

void update_result_with_counts() {
  for (int i = prev_biggest; i >= 0; i--) {
    prev_counts[i] += prev_counts[i + 1];
  }
  for (int i = start; i < end; i++) {
    int next = t[i - start];
    local_result += prev_counts[next + 1];
  }
  //printf("%d %d %lld\n", prev_counts[0], prev_counts[1], local_result);
}

void receive_result() {
  if (node_id != 0) {
    Receive(node_id - 1);
    local_result += GetLL(node_id - 1);
  }
}

void forward_result() {
  if (node_id != number_of_nodes - 1) {
    PutLL(node_id + 1, local_result);
    Send(node_id + 1);
  } else {
    printf("%lld\n", local_result);
  }
}

int main() {
  init();
  compute_local();
  count();
  receive_counts();
  send_counts();
  update_result_with_counts();
  receive_result();
  forward_result();
  return 0;
}