#include <bits/stdc++.h>
#include
using namespace std;
int n, m;
int main() {
cin >> n >> m;
vector<vector > matrix(n, vector(m));
for (int i = 0; i < n; ++i) {
for (int j = 0; j < m; ++j) {
cin >> matrix[i][j];
}
}
vector<vector > dp(m + 1, vector(n + 1, 0));
for (int i = 1; i <= m; ++i) {
int left = 0, right = 0;
for (int j = 1; j <= n; ++j) {
if (i == 1) {
dp[i][j] = 2 * matrix[j - 1][0];
} else {
left += 2 * (matrix[j - 1][0] << (i - 1));
right += 2 * (matrix[j - 1][m - 1] << (i - 1));
}
dp[i][j] = max(dp[i][j - 1], dp[i - 1][j]) + max(left, right);
}
}
cout << dp[m][n] << endl;
return 0;
}
