from collections import deque
n, l, r = map(int, input().split())
g = [list(map(int, input().split())) for _ in range(n)]
dx = [-1, 1, 0, 0]
dy = [0, 0, -1, 1]
def bfs(check, sx, sy, t):
q = deque()
q.append((sx, sy))
check[sx][sy] = t
u_pop = g[sx][sy]
u_num = 1
while q:
x, y = q.popleft()
for i in range(4):
nx, ny = x + dx[i], y + dy[i]
if nx < 0 or ny < 0 or nx >= n or ny >= n:
continue
if check[nx][ny] == -1 and l <= abs(g[nx][ny]-g[x][y]) <= r:
u_pop += g[nx][ny]
u_num += 1
check[nx][ny] = t
q.append((nx, ny))
return check, u_pop, u_num
def move(check, union, g):
for i in range(n):
for j in range(n):
num, pop = union[check[i][j]]
g[i][j] = pop//num
return g
ans = 0
while True:
check = [[-1] * n for _ in range(n)]
t = 0
union = []
for sx in range(n):
for sy in range(n):
if check[sx][sy] == -1:
check, u_pop, u_num = bfs(check, sx, sy, t)
union.append((u_num, u_pop))
t += 1
if len(union) == 0 or len(union) == n * n:
break
g = move(check, union, g)
ans += 1
print(ans)
^^~