#include <bits/stdc++.h> using namespace std; typedef long long ll; typedef long double ld; typedef pair<int, int> pii; typedef pair<ll, int> pli; typedef vector<int> vi; typedef vector<ll> vll; typedef vector<vector<int>> vvi; #define pb push_back #define eb emplace_back #define ppb pop_back #define ppf pop_front #define pf push_front #define bk back() #define frnt front() #define ins insert #define er erase #define sc second #define fr first #define mp make_pair #define mt make_tuple #define lb lower_bound #define ub upper_bound #define REP(i,n) for (int i = 0; i < n; ++i) #define REP1(i,n) for (int i = 1; i <= n; ++i) #define REPV(i,n) for (int i = n-1; i >= 0; --i) #define REPV1(i, n) for (int i = n; i > 0; --i) #define ALL(a) a.begin(), a.end() #define SORT(a) sort(ALL(a)) #define MNTO(x,y) x = min(x, (__typeof__(x))y) #define MXTO(x,y) x = max(x, (__typeof__(x))y) int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n, m; cin >> n >> m; vector<vi> s(n, vi(m)); REP(i, n) { REP(j, m) cin >> s[i][j]; } int totbanana = 0; REP(i, n) { REP(j, m) { totbanana += s[i][j]; } } int ans = INT_MAX; vector<int> a(m); REP(r1, n) { fill(ALL(a), 0); for (int r2 = r1; r2 < n; ++r2) { REP(c, m) a[c] += s[r2][c]; int height = r2-r1+1; int bh = 0, bo = INT_MIN; REP(c, m) { int x = 2*a[c]-height; bh = max(x, bh+x); MXTO(bo, bh); } MNTO(ans, totbanana-bo); } } cout << ans; return 0; }