from heapq import *

N = int(int(input()))
S = [input() for _ in range(N)]
pos = [[] for _ in range(N)]
nxt = [2*N-1] * N 

for i in range(N):
    for j in range(2*N):
        if S[i][j] == "#":
            pos[i].append(j)

cur = 0
needed = [0] * N
ans = 0
for i in range(N):
    num = len(pos[i])
    pos[i].sort(reverse = True)
    for j in range(num):
        if i <= cur:
            ans += abs(i-cur) + abs(pos[i][j] - nxt[cur])
            nxt[cur] -= 1
            if nxt[cur] == N-1:
                cur += 1
        else:
            pos[i+1].append(pos[i][j])

print(ans)