#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
const int MOD = 1e9 + 7;
ll solve(vector<vector<int>>& table){
int n = table.size();
int m = table[0].size();
ll ans = 0;
function<void(int, int, int, int)> DFS = [&](int lx, int rx, int ly, int ry){
cout << "Lx "<< lx << " rx "<< rx << " ly "<< ly << " ry "<< ry << " ans " << ans << endl;
if(rx - lx == 0 && ry - ly == 0) return;
int mn = 1e9;
pair<int, int> cut;
for(int i = ly; i <= ry; i++){
for(int j = lx; j <= rx; j++) ans += table[i][j];
}
for(int i = ly; i < ry; i++){
int up = 0;
int down = 0;
for(int j = ly; j <= i; j++){
for(int q = lx; q <= rx; q++) up += table[j][q];
}
for(int j = i + 1; j <= ry; j++){
for(int q = lx; q <= rx; q++) down += table[j][q];
}
if(abs(up - down) < mn){
mn = abs(up - down);
cut = {i, 0};
}
}
for(int i = lx; i < rx; i++){
int left = 0;
int right = 0;
for(int j = lx; j <= i; j++){
for(int q = ly; q <= ry; q++) left += table[q][j];
}
for(int j = i + 1; j <= rx; j++){
for(int q = ly; q <= ry; q++) right += table[q][j];
}
if(abs(left - right) < mn){
mn = abs(left - right);
cut = {i, 1};
}
}
cout << "Cut "<< cut.first << " " << cut.second << " mn "<< mn << endl;
if(cut.second == 0) {DFS(lx, rx, ly, cut.first); DFS(lx, rx, cut.first + 1, ry);}
else {DFS(lx, cut.first, ly, ry); DFS(cut.first + 1, rx, ly, ry);}
};
DFS(0, m - 1, 0, n - 1);
return ans;
}
mt19937 gen(time(0));
ll solve2(vector<vector<int>>& table){
int n = table.size();
int m = table[0].size();
function<ll(int, int, int, int)> DFS = [&](int lx, int rx, int ly, int ry){
if(rx - lx == 0 && ry - ly == 0) return 0;
ll ans = 1e18;
for(int i = ly; i < ry; i++){
ans = min(ans, DFS(lx, rx, ly, i) + DFS(lx, rx, i + 1, ry));
}
for(int i = lx; i < rx; i++){
ans = min(ans, DFS(lx, i, ly, ry) + DFS(i + 1, rx, ly, ry));
}
for(int i = ly; i <= ry; i++){
for(int j = lx; j <= rx; j++) ans += table[i][j];
}
return (int)ans;
};
return DFS(0, m - 1, 0, n - 1);
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
//freopen("inpt.txt", "r", stdin);
//freopen("out.txt", "w", stdout);
//int tt; cin >> tt;
string s = "RUN";
if(s == "RUN"){
int n, m; cin >> n >> m;
vector<vector<int>> table(n, vector<int>(m));
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++) cin >> table[i][j];
}
cout << solve2(table)<< endl;
return 0;
}/*
int tt = 100000;
for(int t = 1; t <= tt; t++){
int n = gen() % 2 + 2;
int m = gen() % 2 + 2;
vector<vector<int>> table(n, vector<int>(m));
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++) table[i][j] = gen() % 3 + 1;
}
ll ans1 = solve(table);
ll ans2 = solve2(table);
if(ans1 != ans2){
cout << n << " "<< m << endl;
for(auto v : table){
for(int x: v) cout << x << " ";
cout << endl;
}
cout << "Ans1 "<< ans1 << " ans2 "<< ans2 << endl;
return 0;
}
}*/
}
