- #include <bits/stdc++.h>
- using namespace std;
- typedef long long ll;
- typedef long double ld;
- typedef double db;
- typedef string str;
- typedef pair<int,int> pi;
- typedef pair<ll,ll> pl;
- typedef pair<db,db> pd;
- typedef vector<int> vi;
- typedef vector<ll> vl;
- typedef vector<db> vd;
- typedef vector<str> vs;
- typedef vector<pi> vpi;
- typedef vector<pl> vpl;
- typedef vector<pd> vpd;
- #define mp make_pair
- #define f first
- #define s second
- #define sz(x) (int)(x).size()
- #define all(x) begin(x), end(x)
- #define rall(x) (x).rbegin(), (x).rend()
- #define rsz resize
- #define ins insert
- #define ft front()
- #define bk back()
- #define pf push_front
- #define pb push_back
- #define eb emplace_back
- #define lb lower_bound
- #define ub upper_bound
- #define FOR(i,a,b) for (int i = (a); i < (b); ++i)
- #define F0R(i,a) FOR(i,0,a)
- #define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
- #define R0F(i,a) ROF(i,0,a)
- #define trav(a,x) for (auto& a: x)
- const int MOD = 1e9+7; // 998244353;
- const int MX = 2e5+5;
- const ll INF = 1e18;
- const ld PI = acos((ld)-1);
- const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1};
- //mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
- template<class T> bool ckmin(T& a, const T& b) {
- return b < a ? a = b, 1 : 0; }
- template<class T> bool ckmax(T& a, const T& b) {
- return a < b ? a = b, 1 : 0; }
- constexpr int pct(int x) { return __builtin_popcount(x); }
- constexpr int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x))
- ll cdiv(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded up
- ll fdiv(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded down
- ll half(ll x) { return fdiv(x,2); }
- template<class T, class U> T fstTrue(T lo, T hi, U f) {
- hi ++; assert(lo <= hi); // assuming f is increasing
- while (lo < hi) { // find first index such that f is true
- T mid = half(lo+hi);
- f(mid) ? hi = mid : lo = mid+1;
- }
- return lo;
- }
- template<class T, class U> T lstTrue(T lo, T hi, U f) {
- lo --; assert(lo <= hi); // assuming f is decreasing
- while (lo < hi) { // find first index such that f is true
- T mid = half(lo+hi+1);
- f(mid) ? lo = mid : hi = mid-1;
- }
- return lo;
- }
- template<class T> void remDup(vector<T>& v) {
- sort(all(v)); v.erase(unique(all(v)),end(v)); }
- // INPUT
- template<class A> void re(complex<A>& c);
- template<class A, class B> void re(pair<A,B>& p);
- template<class A> void re(vector<A>& v);
- template<class A, size_t SZ> void re(array<A,SZ>& a);
- template<class T> void re(T& x) { cin >> x; }
- void re(db& d) { str t; re(t); d = stod(t); }
- void re(ld& d) { str t; re(t); d = stold(t); }
- template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }
- template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
- template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
- template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
- template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }
- // TO_STRING
- #define ts to_string
- str ts(char c) { return str(1,c); }
- str ts(const char* s) { return (str)s; }
- str ts(str s) { return s; }
- str ts(bool b) {
- #ifdef LOCAL
- return b ? "true" : "false";
- #else
- return ts((int)b);
- #endif
- }
- template<class A> str ts(complex<A> c) {
- stringstream ss; ss << c; return ss.str(); }
- str ts(vector<bool> v) {
- str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
- res += "}"; return res; }
- template<size_t SZ> str ts(bitset<SZ> b) {
- str res = ""; F0R(i,SZ) res += char('0'+b[i]);
- return res; }
- template<class A, class B> str ts(pair<A,B> p);
- template<class T> str ts(T v) { // containers with begin(), end()
- #ifdef LOCAL
- bool fst = 1; str res = "{";
- for (const auto& x: v) {
- if (!fst) res += ", ";
- fst = 0; res += ts(x);
- }
- res += "}"; return res;
- #else
- bool fst = 1; str res = "";
- for (const auto& x: v) {
- if (!fst) res += " ";
- fst = 0; res += ts(x);
- }
- return res;
- #endif
- }
- template<class A, class B> str ts(pair<A,B> p) {
- #ifdef LOCAL
- return "("+ts(p.f)+", "+ts(p.s)+")";
- #else
- return ts(p.f)+" "+ts(p.s);
- #endif
- }
- // OUTPUT
- template<class A> void pr(A x) { cout << ts(x); }
- template<class H, class... T> void pr(const H& h, const T&... t) {
- pr(h); pr(t...); }
- void ps() { pr("\n"); } // print w/ spaces
- template<class H, class... T> void ps(const H& h, const T&... t) {
- pr(h); if (sizeof...(t)) pr(" "); ps(t...); }
- // DEBUG
- void DBG() { cerr << "]" << endl; }
- template<class H, class... T> void DBG(H h, T... t) {
- cerr << ts(h); if (sizeof...(t)) cerr << ", ";
- DBG(t...); }
- // #define LOCAL
- #ifdef LOCAL // compile with -DLOCAL
- #define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
- #else
- #define dbg(...) 0
- #define assert(...) 0
- #endif
- // FILE I/O
- void setIn(str s) { freopen(s.c_str(),"r",stdin); }
- void setOut(str s) { freopen(s.c_str(),"w",stdout); }
- void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
- void setIO(str s = "") {
- unsyncIO();
- // cin.exceptions(cin.failbit);
- // throws exception when do smth illegal
- // ex. try to read letter into int
- if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
- }
- int N;
- const int maxv = 102;
- int pre[maxv][maxv];
- int val[maxv][maxv];
- int main() {
- cin >> N;
- for (int i = 1; i <= N; i++) {
- for (int j = 1; j <= N; j++) {
- cin >> val[i][j];
- pre[i][j] = val[i][j] + pre[i - 1][j] + pre[i][j - 1] - pre[i - 1][j - 1];
- }
- }
- int ans = INT_MIN;
- for (int i1 = 1; i1 <= N; i1++) {
- for (int j1 = 1; j1 <= N; j1++) {
- for (int i2 = i1; i2 <= N; i2++) {
- for (int j2 = j1; j2 <= N; j2++) {
- ans = max(ans, pre[i2][j2] - pre[i1 - 1][j2] - pre[i2][j1 - 1] + pre[i1 - 1][j1 - 1]);
- }
- }
- }
- }
- cout << ans;
- }