from collections import deque

N = int(input())

area = []
shark = (0,0)

for i in range(N) :    
    area.append(list(map(int, input().split())))
    for j in range(N) :
        if area[i][j] == 9 :
            shark = (i,j)
            area[i][j] = 0

# 현재 상어의 위치에서 먹을 수 있는 물고기들 중
# 우선순위가 가장 높은 물고기의 위치와 거리를 반환하는 함수
# 입력변수는 현재 상어의 위치좌표((y,x) 형태의 튜플)와 상어의 크기
def fish(current, size) :
    y, x = current
    visited = [[False]*N for _ in range(N)]
    q = deque()
    q.append((x,y,0))
    visited[y][x] = True
    result = []
    
    while q :
        cur_x, cur_y, cur_dist = q.popleft()
        
        for dx, dy in [(-1,0), (1,0), (0,1), (0,-1)] :
            next_x, next_y = cur_x + dx, cur_y + dy

            if 0<=next_x<N and 0<=next_y<N and not visited[next_y][next_x] and area[next_y][next_x] <= size :
                q.append((next_x, next_y, cur_dist + 1))
                visited[next_y][next_x] = True

                if 0<area[next_y][next_x]<size :
                    result.append((next_x, next_y, cur_dist + 1))
    
    if result :
        result.sort(key=lambda x: (x[2], x[1], x[0]))
        return result[0]
    else :
        return None

shark_size = 2
eatCount = 0
total_time = 0

while (res := fish(shark, shark_size)) is not None :
    cur_x, cur_y, dist = res

    shark = (cur_y, cur_x)
    area[cur_y][cur_x] = 0
    total_time += dist
    eatCount += 1
    
    if eatCount == shark_size :
        eatCount = 0
        shark_size += 1

print(total_time)