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#include "dzialka.h"
#include "message.h"

#include <algorithm>
#include <cstdio>
#include <vector>

using namespace std;

typedef long long LL;

int main() {
  int nodes = NumberOfNodes(); 
  int node_id = MyNodeId(); 
  int h = GetFieldHeight();
  int w = GetFieldWidth();

  // Prepare
  vector<int> currs;
  for (int i=node_id; i<w; i+=nodes) {
    currs.push_back(0);
  }

  for (int j=0; j<h; ++j) {
    for (int i=node_id; i<w; i+=nodes) {
      auto& curr = currs[(i-node_id) / nodes];
      ++curr;
      if (!IsUsableCell(j, i)) {
        curr = 0;
      }
      PutInt(j%nodes, curr);
    }
  }

  // Shuffle
  for (int i=0; i<nodes; ++i) {
    Send(i);
  }
  for (int i=0; i<nodes; ++i) {
    Receive(i);
  }

  // Compute
  LL result = 0;
  for (int j=node_id; j<h; j+=nodes) {
    vector<pair<int, int>> stack; // (positiion, distance)
    for (int i=0; i<w+1; ++i) {
      int dist = (i<w) ? GetInt(i%nodes) : 0;
      int pos = i;
      while (!stack.empty() && stack.back().second >= dist) {
        int len = (i - stack.back().first);
        int diff = stack.back().second - dist;
        if (stack.size() > 1) {
          diff = min(diff, stack.back().second - stack[stack.size() - 2].second);
        }
        LL gain = (LL)diff * len * (len+1) / 2;
        result += gain; 
        pos = stack.back().first;
        stack.pop_back();
      }
      stack.push_back(make_pair(pos, dist));
    }
  }

  // Aggregate
  if (node_id != 0) {
    PutLL(0, result);
    Send(0);
  } else {
    for (int i=1; i<nodes; ++i) {
      Receive(i);
      result += GetLL(i);
    }
    printf("%lld\n", result);
  }

  return 0;
}