#include <bits/stdc++.h>
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int n, m;
std::cin >> n >> m;
std::vector<std::vector<int64_t>> a(n + 1, std::vector<int64_t>(m + 1));
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) {
std::cin >> a[i][j];
}
}
int64_t ans = -1e18;
/**
for(int x = 1; x <= n; x++) {
for(int y = 1; y <= m; y++) {
for(int x1 = 1; x1 <= n; x1++) {
for(int y1 = 1; y1 <= m; y1++) {
int64_t cost = a[x][y] - a[x1][y1];
int64_t path = x1 - x + y1 - y;
ans = std::max(ans, cost - path);
}
}
}
}**/
// x > x1 && y > y1
// a[x][y] - a[x1][y1] - (x - x1 + y - y1)
// a[x][y] - a[x1][y1] - x + x1 - y + y1
std::vector<std::vector<int64_t>> dp(n + 2, std::vector<int64_t>(m + 2));
for(int i = 0; i <= n + 1; i++) {
for(int j = 0; j <= m + 1; j++) {
dp[i][j] = -1e18;
}
}
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) {
dp[i][j] = std::max(dp[i - 1][j], dp[i][j - 1]);
dp[i][j] = std::max(dp[i][j], - a[i][j] + i + j - 1);
ans = std::max(ans, a[i][j] - i - j + dp[i][j]);
}
}
for(int i = 0; i <= n + 1; i++) {
for(int j = 0; j <= m + 1; j++) {
dp[i][j] = -1e18;
}
}
// x > x1 && y < y1
// a[x][y] - a[x1][y1] - (x - x1 + y1 - y)
// a[x][y] - a[x1][y1] - x + x1 - y1 + y
for(int j = m; j >= 1; j--) {
for(int i = 1; i <= n; i++) {
dp[i][j] = std::max(dp[i - 1][j], dp[i][j + 1]);
dp[i][j] = std::max(dp[i][j], - a[i][j] + i - j - 1);
ans = std::max(ans, a[i][j] - i + j + dp[i][j]);
}
}
for(int i = 0; i <= n + 1; i++) {
for(int j = 0; j <= m + 1; j++) {
dp[i][j] = -1e18;
}
}
// x < x1 && y > y1
// a[x][y] - a[x1][y1] - (x1 - x + y - y1)
// a[x][y] - a[x1][y1] - x1 + x - y + y1
for(int j = 1; j <= m; j++) {
for(int i = n; i >= 1; i--) {
dp[i][j] = std::max(dp[i + 1][j], dp[i][j - 1]);
dp[i][j] = std::max(dp[i][j], - a[i][j] - i + j - 1);
ans = std::max(ans, a[i][j] + i - j + dp[i][j]);
}
}
for(int i = 0; i <= n + 1; i++) {
for(int j = 0; j <= m + 1; j++) {
dp[i][j] = -1e18;
}
}
// x < x1 && y < y1
// a[x][y] - a[x1][y1] - (x1 - x + y1 - y)
for(int j = m; j >= 1; j--) {
for(int i = n; i >= 1; i--) {
dp[i][j] = std::max(dp[i][j + 1], dp[i + 1][j]);
dp[i][j] = std::max(dp[i][j], - a[i][j] - i - j - 1);
ans = std::max(ans, a[i][j] + i + j + dp[i][j]);
}
}
std::cout << ans;
}
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