static void Method(string[] args)
{
int[] hw = ReadInts();
int h = hw[0];
int w = hw[1];
bool[,] grid = new bool[h, w];
for (int i = 0; i < h; i++)
{
string s = Read();
for (int j = 0; j < w; j++)
{
grid[i, j] = s[j] == '.';
}
}
int all = h * w;
/*int res = 0;
* for(int i = 0; i < all; i++)
* {
* for(int j = 0; j < all; j++)
* {
* if (!grid[i / w, i % w] || !grid[j / w, j % w]) continue;
* Queue<int[]> que = new Queue<int[]>();
* que.Enqueue(new int[2] { i, 0 });
* bool[,] visited = new bool[h, w];
* while (que.Count > 0)
* {
* int[] val = que.Dequeue();
* int now = val[0];
* int cost = val[1];
* if (visited[now / w, now % w]) continue;
* if (now == j)
* {
* res = Max(res, cost);
* break;
* }
*
* if (now / w > 0 && grid[now / w - 1, now % w]
* && !visited[now / w - 1, now % w])
* {
* que.Enqueue(new int[2] { now - w, cost + 1 });
* }
* if (now / w + 1 < h && grid[now / w + 1, now % w]
* && !visited[now / w + 1, now % w])
* {
* que.Enqueue(new int[2] { now + w, cost + 1 });
* }
* if (now %w>0 && grid[now / w, now % w-1]
* && !visited[now / w, now % w-1])
* {
* que.Enqueue(new int[2] { now - 1, cost + 1 });
* }
* if (now % w+1< w && grid[now / w, now % w + 1]
* && !visited[now / w, now % w + 1])
* {
* que.Enqueue(new int[2] { now + 1, cost + 1 });
* }
* }
* }
* }
* WriteLine(res);
*/
WarshallFloyd warshall = new WarshallFloyd(all);
for (int i = 0; i < all; i++)
{
for (int j = 0; j < all; j++)
{
warshall.costs[i, j] = int.MaxValue;
if (i == j)
{
warshall.costs[i, j] = 0;
}
if ((i / w > 0 && i - j == w) ||
(i / w + 1 < h && j - i == w) ||
(i % w > 0 && i - j == 1) ||
(i % w + 1 < w && j - i == 1))
{
warshall.costs[i, j] = 1;
}
}
}
warshall.Calculate(grid, w);
long res = 0;
for (int i = 0; i < all; i++)
{
for (int j = 0; j < all; j++)
{
if (!grid[i / w, i % w] || !grid[j / w, j % w])
{
continue;
}
if (warshall.costs[i, j] == int.MaxValue)
{
continue;
}
res = Max(res, warshall.costs[i, j]);
}
}
WriteLine(res);
}
static void Solve(IO io)
{
var n = io.I;
var a = new long[n, n];
var gr = new AdjacencyMatrix <long>(n,
new Monoid <long>(0, Sum), new Monoid <long>(long.MaxValue, Min));
for (var i = 0; i < n; i++)
{
for (var j = 0; j < n; j++)
{
gr[i, j] = a[i, j] = io.L;
}
}
var wf = new WarshallFloyd <long>(gr);
wf.Calculate();
var sum = 0L;
for (var i = 0; i < n; i++)
{
for (var j = 0; j < n; j++)
{
sum += wf.GetMinCost(i, j);
}
}
if (a.Cast <long>().Sum() != sum)
{
io.Write(-1);
return;
}
var ans = 0L;
for (var i = 0; i < n; i++)
{
for (var j = 0; j < n; j++)
{
var flg = true;
for (var k = 0; k < n; k++)
{
if (i == j || i == k || j == k)
{
continue;
}
if (a[i, j] >= a[i, k] + a[k, j])
{
flg = false;
break;
}
// Error.WriteLine($"{i} {j} {k} {a[i, j]} {a[i, k]} {a[k, j]} {(a[i, j] < a[i, k] + a[k, j] ? '!' : ' ')}");
}
if (flg)
{
ans += a[i, j];
}
}
}
io.Write(ans >> 1);
}
