| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| #include<iostream> |
| #include<cstdio> |
| #include<algorithm> |
| #include<climits> |
| #include<cstring> |
| #include<string> |
| #include<sstream> |
| #include<cmath> |
| #include<vector> |
| #include<queue> |
| #include<cstdlib> |
| #include<deque> |
| #include<stack> |
| #include<map> |
| #include<set> |
| #define __FastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0) |
| #define __FileRead freopen ("input.txt", "r", stdin); |
| #define __FileWrite freopen ("output.txt", "w", stdout); |
| #define SET(a,v) memset(a,v,sizeof(a)) |
| #define pii pair<int,int> |
| #define pll pair <ll, ll> |
| #define debug cout <<"#########\n"; |
| #define nl cout << "\n"; |
| #define sp cout << " "; |
| #define sl(n) scanf("%lld", &n) |
| #define sf(n) scanf("%lf", &n) |
| #define si(n) scanf("%d", &n) |
| #define ss(n) scanf("%s", n) |
| #define pf(n) scanf("%d", n) |
| #define pfl(n) scanf("%lld", n) |
| #define all(v) v.begin(), v.end() |
| #define Pow2(x) ((x)*(x)) |
| #define Mod(x, m) ((((x) % (m)) + (m)) % (m)) |
| #define Max3(a, b, c) max(a, max(b, c)) |
| #define Min3(a, b, c) min(a, min(b, c)) |
| #define pb push_back |
| #define mk make_pair |
| #define MAX 105 |
| #define INF 1000000000 |
| #define MOD 1000000007 |
| using namespace std; |
| typedef long long ll; |
| typedef unsigned long long ull; |
|
|
| template <typename T> |
| std::string NumberToString ( T Number ) { |
| std::ostringstream ss; |
| ss << Number; |
| return ss.str(); |
| } |
| ll lcm (ll a, ll b) { |
| return a * b / __gcd (a, b); |
| } |
| |
| int tree[MAX * 4][MAX * 4]; |
| int vec[MAX][MAX]; |
| int n, m, mx; |
| void build (int indx, int nod, int low, int high) { |
| if (low == high) { |
| tree[indx][nod] = low; |
| return ; |
| } |
|
|
| int mid = (high + low) / 2; |
| int left = nod * 2; |
| int right = nod * 2 + 1; |
| build (indx, left, low, mid); |
| build (indx, right, mid + 1, high); |
|
|
| if (vec[indx][tree[indx][left]] <= vec[indx][tree[indx][right]]) { |
| tree[indx][nod] = tree[indx][left]; |
|
|
| } else { |
| tree[indx][nod] = tree[indx][right]; |
| } |
| } |
| int query (int indx, int nod, int low, int high, int qlow, int qhigh) { |
| if (qlow > high || qhigh < low) { |
| return 0; |
| } |
|
|
| if (qlow <= low && qhigh >= high) { |
| return tree[indx][nod]; |
| } |
|
|
| int mid = (high + low) / 2; |
| int left = nod * 2; |
| int right = nod * 2 + 1; |
| int a = query (indx, left, low, mid, qlow, qhigh); |
| int b = query (indx, right, mid + 1, high, qlow, qhigh); |
|
|
| if (vec[indx][a] <= vec[indx][b]) { |
| return a; |
|
|
| } else { |
| return b; |
| } |
| } |
| void solve (int indx, int l, int r) { |
| if (l > r) return ; |
|
|
| int idx = query (indx, 1, 1, m, l, r); |
| int xx = vec[indx][idx] * (r - l + 1); |
| mx = max (mx, xx); |
| solve (indx, l, idx - 1); |
| solve (indx, idx + 1, r); |
| } |
| int main () { |
| __FastIO; |
| while (cin >> n >> m) { |
| if (n == 0 && m == 0) break; |
|
|
| SET (tree, 0); |
| SET (vec, 0); |
| int ar[MAX][MAX]; |
|
|
| for (int i = 1; i <= n; i++) { |
| for (int j = 1; j <= m; j++) { |
| cin >> ar[i][j]; |
| } |
| } |
|
|
| for (int i = 1; i <= n; i++) { |
| for (int j = 1; j <= m; j++) { |
| if (i == 1) { |
| if (ar[i][j] == 0) { |
| vec[i][j] = 1; |
|
|
| } else { |
| vec[i][j] = 0; |
| } |
|
|
| } else { |
| if (ar[i][j] == 0) { |
| vec[i][j] = vec[i - 1][j] + 1; |
|
|
| } else { |
| vec[i][j] = 0; |
| } |
| } |
| } |
| } |
|
|
| for (int i = 0; i < MAX; i++) { |
| vec[i][0] = 1000000; |
| } |
|
|
| int ans = 0; |
|
|
| for (int i = 1; i <= n; i++) { |
| build (i, 1, 1, m); |
| } |
|
|
| for (int i = 1; i <= n; i++) { |
| mx = 0; |
| solve (i, 1, m); |
| ans = max (ans, mx); |
| } |
|
|
| cout << ans << "\n"; |
| } |
|
|
| return 0; |
| } |
|
|
