//In The Name Of ALLAH! #pragma GCC optimize("O3") #include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> using namespace __gnu_pbds; using namespace std; #define ll long long #define ld long double #define endl '\n' #define pb push_back #define pf push_front #define Zemur007 ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); #define bpc __builtin_popcountll #define btz __builtin_ctzll #define all(x) x.begin() , x.end() #define allr(x) x.rbegin() , x.rend() #define F first #define S second #define pll pair<ll , ll> #define turtle tuple<ll , ll , ll> #define pss pair<string , string> #define YES cout << "YES" << endl; #define NO cout << "NO" << endl; #define indexed_set tree<pll , null_type , less<pll> , rb_tree_tag , tree_order_statistics_node_update> const ll sz = 2e3 + 5e2 + 5 , INF = 1e18 , MOD = 1e9 + 7; char a[sz][sz]; ll mask , i , j , k; void solve(){ ll n , m; cin >> n >> m; for(i = 1 ; i <= n ; i++){ for(j = 1 ; j <= m ; j++){ cin >> a[i][j]; } } ll row = n , col = m; for(i = 1 ; i <= n ; i++){ ll cnt = 0; for(j = 1 ; j <= m ; j++){ if(a[i][j] == '1') cnt++; else{ if(cnt) col = min(col , cnt); cnt = 0; } } if(cnt) col = min(col , cnt); } for(j = 1 ; j <= m ; j++){ ll cnt = 0; for(i = 1 ; i <= n ; i++){ if(a[i][j] == '1') cnt++; else{ if(cnt) row = min(row , cnt); cnt = 0; } } if(cnt) row = min(row , cnt); } cout << row * col << endl; } signed main(){ Zemur007; // open; ll t = 1; // cin >> t; while(t--){ solve(); } // for(ll testcase = 1 ; testcase <= t ; testcase++){ // cout << "Case " << testcase << ":" << endl; // solve(); // } }