from collections import deque
import copy

n = int(input())
p = list(map(int, input()))
for i in range(len(p)):
    p[i] -= 1

to_outsides = [[0 for _ in range(n)] for _ in range(n)]
not_exist = [["■" for _ in range(n)] for _ in range(n)]


for i in range(n):
    for j in range(n):
        to_outside = [i,n-1-i,j,n-1-j]
        to_outsides[i][j] = min(to_outside)

directions = [[-1,0],[1,0],[0,-1],[0,1]]

all_loss = 0
answer = 0
for i, person in enumerate(p):
    exited = [person//n, person%n]
    answer += to_outsides[exited[0]][exited[1]]
    not_exist[exited[0]][exited[1]] = "□"
    seen = []
    seen.append([exited[0],exited[1]])
    todo = deque([exited])
    renews = []
    while len(todo)>0:
        now = todo.pop()
        renews.append(now)
        for direction in directions:
            try:
                checking = [now[0]+direction[0],now[1]+direction[1]]
                to_outsides[checking[0]][checking[1]]
            except:
                continue
            if [checking[0],checking[1]] not in seen and\
            ((not_exist[checking[0]][checking[1]] == "□" and  to_outsides[checking[0]][checking[1]]==to_outsides[now[0]][now[1]])or\
            to_outsides[checking[0]][checking[1]]>to_outsides[now[0]][now[1]]):
                todo.append([checking[0],checking[1]])
                seen.append([checking[0],checking[1]])
    
    for renew in renews:
        if to_outsides[renew[0]][renew[1]] != 0:
            to_outsides[renew[0]][renew[1]]-=1
print(answer)