#include <bits/stdc++.h> #define fi first #define se second #define mp make_pair #define pb push_back #define eb emplace_back using namespace std; typedef long long ll; typedef pair<int, int> ii; vector<vector<int>> a; int N, M, sum = 0; signed main(void) { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); #ifdef LOCAL freopen("A.INP", "r", stdin); freopen("A.OUT", "w", stdout); #endif // LOCAL cin >> N >> M; a.assign(N + 5, vector<int>(M + 5)); for(int i = 1; i <= N; ++i){ for(int j = 1; j <= M; ++j){ cin >> a[i][j]; sum += a[i][j]; if(a[i][j] == 0) a[i][j] = 1; else a[i][j] = -1; } } int res = 1e9; for(int r = 1; r <= N; ++r){ vector<int> col(M + 5, 0); for(int i = r; i >= 1; --i){ for(int j = 1; j <= M; ++j) col[j] += a[i][j]; int ps = 0; int mn = 0; for(int j = 1; j <= M; ++j){ ps += col[j]; res = min(res, ps - mn); mn = max(mn, ps); } } } cout << res + sum; }