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#include <cstdlib>
#include <cstdio>
#include <iostream>

#include "krazki.h"
#include "message.h"

using namespace std;

int main() {
	int nodes = NumberOfNodes();
	int id = MyNodeId(); // 0..nodes-1
	int n = PipeHeight();
	int m = NumberOfDiscs();

	int discGroupSize = min(max(n / nodes, 1), m);
	int discGroups = max(1, m / discGroupSize);
	int *DA = (int*) calloc(discGroups, sizeof(*DA)); // disc group begin
	int *DB = (int*) calloc(discGroups, sizeof(*DB)); // disc group end
	long long int *DM = (long long int*) calloc(discGroups, sizeof(*DM)); // disc group max (or -1 if there is no group)

	if (id == 0) {
		DA[0] = 1; DB[0] = discGroupSize;
		PutInt(nodes-1, DA[0]);
		PutInt(nodes-1, DB[0]);
		Send(nodes-1);
		for (int i = 1; i < discGroups; i++) {
			DA[i] = DA[i-1] + discGroupSize;
			DB[i] = i == discGroups - 1 ? m : DB[i-1] + discGroupSize;
			int node = (i-1) % (nodes-1) + 1;
			PutInt(node, DA[i]);
			PutInt(node, DB[i]);
			Send(node);
		}

		Receive(nodes-1);
		DM[0] = GetLL(nodes-1);
		//fprintf(stderr, "Received DM[i=%d] = %d from %d\n", 0, DM[0], nodes-1);
		for (int i = 1; i < discGroups; i++) {
			int node = (i-1) % (nodes-1) + 1;
			Receive(node);
			DM[i] = GetLL(node);
			//fprintf(stderr, "Received DM[i=%d] = %d from %d\n", i, DM[i], node);
		}

		for (int i = 1; i < nodes; i++) {
			PutInt(i, -1);
			Send(i);
		}
	} else {
		while (1) {
			Receive(0);
			int da = GetInt(0);
			if (da == -1) {
				break;
			}

			int db = GetInt(0);
			//fprintf(stderr, "Received request from coord for DM, DA=%d, DB=%d\n", da, db);
			long long int dm = -1;
			for (int i = da; i <= db; i++) {
				dm = max(dm, DiscDiameter(i));
			}

			PutLL(0, dm);
			Send(0);
		}
	}

	int pipeGroupSize = max(n / nodes, 1);
	int pipeA = id * pipeGroupSize + 1;
	int pipeB = id < nodes-1 ? pipeA + pipeGroupSize - 1 : n;
	int lastNode = pipeB == n ? 1 : 0; // is this the node containing last hole

	int pipeS = pipeB - pipeA + 1; // pipeA: 2, pipeB: 5, pipeS: 4 (2, 3, 4, 5)
	if (pipeA > n) {
		if (id+1 <= nodes-1) {
			PutInt(id+1, -1);
			Send(id+1);
		}

		Receive(id-1);
		int x = GetInt(id-1);
		PutInt(0, n+1);
		Send(0);
		return EXIT_SUCCESS;
	}

	long long int *H = (long long int*) calloc(pipeS, sizeof(*H));
	H[0] = HoleDiameter(pipeA);
	for (int i = 1; i < pipeS; i++) {
		H[i] = min(H[i-1], HoleDiameter(pipeA+i));
	}

	//fprintf(stderr, "pipeA: %d, pipeB: %d, lastNode: %d, pipeS: %d, H[pipeL]: %d\n", pipeA, pipeB, lastNode, pipeS, H[pipeS-1]);

	for (int i = 0; i < pipeS; i++) {
		H[i] = -H[i];
		//cerr << H[i] << endl;
	} // now H[0..pipeS-1] contains diameters in non-descending order, like: -5, -5, -4, -2, -2

	int pipeL = pipeS-1; // index to last pipe element that is unused yet
	int result = n+1;
	//cerr << "blabla" << endl;
	if (id == 0) {
		for (int i = 0; i < discGroups && DM[i] > 0 && result == n+1; i++) {
			//cerr << "blabla" << endl;
			// considering disc group DA[i]..DB[i], whose max diameter is DM[i]
			if (-H[pipeS-1] >= DM[i] && !lastNode) { // every element can go further, sending it to the next node and waiting for result
				PutInt(1, DA[i]);
				PutInt(1, DB[i]);
				PutLL(1, DM[i]);
				Send(1);
				//fprintf(stderr, "sent da=%d, db=%d, dm=%d\n", DA[i], DB[i], DM[i]);
				Receive(1);
				int eaten = GetInt(1); // how many has the next one eaten
				//fprintf(stderr, "eaten by children: %d\n", eaten);
				DA[i] += eaten;
			} else {
				int da = DA[i];
				int db = DA[i] - 1;
				long long dm = DiscDiameter(DA[i]);
				while (db+1 <= DB[i] && DiscDiameter(db+1) <= -H[pipeS-1]) {
					db++;
					dm = max(dm, DiscDiameter(db));;
				}
				if (da <= db) {
					//fprintf(stderr, "sending over just a part\n");
					PutInt(1, da);
					PutInt(1, db);
					PutLL(1, dm);
					Send(1);
					//fprintf(stderr, "sent da=%d, db=%d, dm=%d\n", da, db, dm);
					Receive(1);
					int eaten = GetInt(1); // how many has the next one eaten
					//fprintf(stderr, "eaten by children: %d\n", eaten);
					DA[i] += eaten;
				} else {
					//fprintf(stderr, "not sending da=%d, db=%d, dm=%d\n", DA[i], DB[i], DM[i]);
				}
			}

			// eating the rest (possibly nothing, if everything has been eaten)
			for (int j = DA[i]; j <= DB[i]; j++) {
				//cerr << "eating the rest" << endl;
				long long int dd = DiscDiameter(j);
				while (pipeL >= 0 && (-H[pipeL]) < dd) {
					H[pipeL--] = 0;
				}

				if (pipeL < 0) { // trying to put disc but no more space. end result = 0
					result = 0;
					//fprintf(stderr, "result = 0\n");
					break;
				} else {
					H[pipeL--] = 0;
				}
			}
			//fprintf(stderr, "pipeL: %d\n", pipeL);
		}

		PutInt(1, -1);
		Send(1);
	} else {
		while (1) {
			Receive(id - 1);
			int da = GetInt(id - 1);
			if (da == -1) {
				if (id+1 <= nodes-1) {
					PutInt(id+1, -1);
					Send(id+1);
				}

				PutInt(0, pipeL == pipeS-1 ? n+1 : pipeA + pipeL + 1);
				Send(0);
				break;
			}

			int db = GetInt(id - 1);
			long long int dm = GetLL(id - 1);
			//fprintf(stderr, "Got eating request da=%d, db=%d, dm=%d\n", da, db, dm);

			if (-H[pipeS-1] >= dm && id + 1 <= nodes-1 && !lastNode) { // every element can go further, sending it to the next node and waiting for result
				//fprintf(stderr, "Eating in full, notifying parent\n");
				PutInt(id-1, db - da + 1);
				Send(id-1);
				PutInt(id+1, da);
				PutInt(id+1, db);
				PutLL(id+1, dm);
				Send(id+1);
				Receive(id+1);
				int eaten = GetInt(id+1); // how many has the next one eaten
				//fprintf(stderr, "Child has eaten %d\n", eaten);
				da += eaten;
				for (int j = da; j <= db; j++) {
					// eating the rest (possibly nothing, if everything has been eaten)
					H[pipeL--] = 0;
					//fprintf(stderr, "Eating...\n");
				}
			} else {
				//fprintf(stderr, "Cannot eat in full, tryint to send part and then eat locally\n");
				int da2 = da;
				int db2 = da - 1;
				long long dm2 = DiscDiameter(da2);
				int eaten = 0;
				while (db2+1 <= db && DiscDiameter(db2+1) <= -H[pipeS-1]) {
					db2++;
					dm2 = max(dm2, DiscDiameter(db2));;
				}
				if (da2 <= db2 && id + 1 <= nodes-1 && !lastNode) {
					//fprintf(stderr, "sending over just a part\n");
					PutInt(id+1, da2);
					PutInt(id+1, db2);
					PutLL(id+1, dm2);
					Send(id+1);
					//fprintf(stderr, "sent da=%d, db=%d, dm=%d\n", da2, db2, dm2);
					Receive(id+1);
					eaten = GetInt(id+1); // how many has the next one eaten
					//fprintf(stderr, "eaten by children: %d\n", eaten);
					da += eaten;
				} else {
					//fprintf(stderr, "not sending da=%d, db=%d, dm=%d\n", da, db, dm);
				}
				
				//fprintf(stderr, "pipeL: %d, da: %d, db: %d\n", pipeL, da, db);
				for (int j = da; j <= db; j++) {
					long long int dd = DiscDiameter(j);
					while (pipeL >= 0 && (-H[pipeL]) < dd) {
						//fprintf(stderr, "eating here blocked as DD(j=%d) == %d, and H[pipeL=%d]=%d\n", j, dd, pipeL, H[pipeL]);
						H[pipeL--] = 0;
					}

					if (pipeL < 0) {
						//fprintf(stderr, "breaking\n");
						break;
					} else {
						H[pipeL--] = 0;
						eaten++;
					}
				}
				//fprintf(stderr, "pipeL: %d\n", pipeL);
				//fprintf(stderr, "Notifying parent about eaten=%d\n", eaten);
				PutInt(id-1, eaten);
				Send(id-1);
			}
		}
	}

	if (id > 0) {
		return EXIT_SUCCESS;
	}

	result = min(result, pipeL == pipeS-1 ? n+1 : pipeA + pipeL + 1);
	for (int i = 1; i < nodes; i++) {
		Receive(i);
		int m = GetInt(i);
		//cerr << "Result from " << i << " is " << m << endl;
		result = min(result, m);
	}

	cout << result << endl;
	return EXIT_SUCCESS;
}