#include <iostream>
#include <vector>
#include <queue>

using namespace std;


int n, l, r;
int moveCount = 0;
int befCount = -1;
vector<vector<int>> country;
vector<vector<int>> visited;
vector<pair<int, int>> group;
void resetVisited() {
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			visited[i][j] = 0;
		}
	}
}
bool checkBoundary(int y, int x, int m) {
	if (y < 0 || x < 0)
		return false;
	if (y >= n || x >= n)
		return false;

	if (visited[y][x] == 1)
		return false;
	if (abs(country[y][x] - m) >= l && abs(country[y][x] - m) <= r)
		return true;
	return false;
}
void bfs(int y, int x) {
	int count = 1;
	int m = 0;
	int sum = 0;
	queue<pair<int, int>> checkGroup;
	checkGroup.push(make_pair(y, x));
	group[0] = make_pair(y, x);
	visited[y][x] = 1;
	while (!checkGroup.empty()) {
		y = checkGroup.front().first;
		x = checkGroup.front().second;
		m = country[y][x];
		checkGroup.pop();
		y--;
		if (checkBoundary(y, x, m)) {
			checkGroup.push(make_pair(y, x));
			group[count] = make_pair(y, x);
			count++;
			visited[y][x] = 1;

		}
		y += 2;
		if (checkBoundary(y, x, m)) {
			checkGroup.push(make_pair(y, x));
			group[count] = make_pair(y, x);
			count++;
			visited[y][x] = 1;

		}
		y--;
		x--;
		if (checkBoundary(y, x, m)) {
			checkGroup.push(make_pair(y, x));
			group[count] = make_pair(y, x);
			count++;
			visited[y][x] = 1;

		}
		x += 2;
		if (checkBoundary(y, x, m)) {
			checkGroup.push(make_pair(y, x));
			group[count] = make_pair(y, x);
			count++;
			visited[y][x] = 1;

		}
	}
	if (count > 1) {
		if(moveCount == befCount)
			moveCount++;
		for (int i = 0; i < count; i++) {
			sum += country[group[i].first][group[i].second];
		}
		for (int i = 0; i < count; i++) {
			country[group[i].first][group[i].second] = sum / count;
		}
	}
}
int main() {
	int temp;
	cin >> n >> l >> r;

	country.assign(n, vector<int>(n, 0));
	visited.assign(n, vector<int>(n, 0));
	group.assign(2500, make_pair(0, 0));

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			cin >> temp;
			country[i][j] = temp;
		}
	}
	while (moveCount != befCount) {
		befCount = moveCount;
		resetVisited();
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) {
				if (visited[i][j] == 0)
					bfs(i, j);
			}
		}
	}
	cout << moveCount;
	/*for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			cout << country[i][j] << " ";
		}
		cout << endl;
	}*/
	return 0;
}