#include <cstdio>#include <cstring>#include <iostream>using namespace std;typedef __int64 ll;const ll inf = 0x7fffffffffffffff;ll minn;int n, m;ll dp[505][505];int mapn[505][505];inline ll abs(ll a){ return a >= 0 ? a : -a;}void Init() { for(int i = 0; i <= n || i <= m; i++){ dp[i][0] = dp[0][i] = 0; } for(int i = 1; i <= n; i++){ for(int k = 1; k <= m; k++){ dp[i][k] =dp[i-1][k] + dp[i][k-1] - dp[i-1][k-1] + mapn[i][k]; } }}inline ll fun(int up, int dw, int lf, int rg) { ll sum = 0; sum += dp[dw][rg] + dp[up-1][lf-1] - dp[up-1][rg] - dp[dw][lf-1]; return sum;}inline void ***(ll sum1, ll sum2, ll sum3){ ll sum = abs(sum1 - sum2) + abs(sum1 - sum3) + abs(sum2 - sum3); if(sum < minn) minn = sum;}int main(){ while(scanf("%d%d", &n, &m) && (m || n)){ for(int i = 1; i <= n; i++){ for(int k = 1; k <= m; k++){ scanf("%d", &mapn[i][k]); } } Init(); minn = inf; for(int i = 1; i < n; i++){ for(int k = 1; k < m; k++){ ll sum1 = fun(1, i, 1, k); ll sum2 = fun(1, i, k+1, m); ll sum3 = fun(i+1, n, 1, k); ll sum4 = fun(i+1, n, k+1, m); ***(sum1+sum2, sum3, sum4); ***(sum1+sum3, sum2, sum4); ***(sum2+sum4, sum1, sum3); ***(sum3+sum4, sum1, sum2); } } for(int i = 1; i < n-1; i++){ ll sum1 = fun(1, i, 1, m); for(int k = i+1; k < n; k++){ ll sum2 = fun(i+1, k, 1, m); ll sum3 = fun(k+1, n, 1, m); ***(sum1, sum2, sum3); } } for(int i = 1; i < m-1; i++){ ll sum1 = fun(1, n, 1, i); for(int k = i+1; k < m; k++){ ll sum2 = fun(1, n, i+1, k); ll sum3 = fun(1, n, k+1, m); ***(sum1, sum2, sum3); } } printf("%I64dn", minn); } return 0;}
