//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,avx512f") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DEBUG #include "./CompetitiveProgrammingCpp/debug.hpp" #include "./CompetitiveProgrammingCpp/Timer.hpp" #include "./CompetitiveProgrammingCpp/sample.hpp" #else #define dump(...) #endif /* macro */ #define FOR(i, b, e) for(ll i = (ll)(b); i < (ll)(e); ++i) #define RFOR(i, b, e) for(ll i = (ll)((e)-1); i >= (ll)(b); --i) #define REP(i, n) FOR(i, 0, (n)) #define RREP(i, n) RFOR(i, 0, (n)) #define REPC(x,c) for(const auto& x:(c)) #define REPI2(it,b,e) for(auto it = (b); it != (e); ++it) #define REPI(it,c) REPI2(it, (c).begin(), (c).end()) #define RREPI(it,c) REPI2(it, (c).rbegin(), (c).rend()) #define REPI_ERACE2(it, b, e) for(auto it = (b); it != (e);) #define REPI_ERACE(it, c) REPI_ERACE2(it, (c).begin(), (c).end()) #define ALL(x) (x).begin(),(x).end() #define cauto const auto& /* macro func */ template inline auto sort(T& t) { std::sort(ALL(t)); } template inline auto rsort(T& t) { std::sort((t).rbegin(), (t).rend()); } template inline auto unique(T& t) { (t).erase(unique((t).begin(), (t).end()), (t).end()); } template inline auto chmax(T& t, const S& s) { if(s > t) { t = s; return true; } return false; } template inline auto chmin(T& t, const S& s) { if(s < t) { t = s; return true; } return false; } inline auto BR() { std::cout << "\n"; } /* type define */ using ll = long long; using VS = std::vector; using VL = std::vector; using VVL = std::vector; using VVVL = std::vector; using VVVVL = std::vector; using VVVVVL = std::vector; using VD = std::vector; template using V = std::vector; template using P = std::pair; using PAIR = P; /* using std */ using std::cout; constexpr char endl = '\n'; using std::cin; using std::pair; using std::string; using std::stack; using std::queue; using std::deque; using std::vector; using std::list; using std::map; using std::unordered_map; using std::multimap; using std::unordered_multimap; using std::set; using std::unordered_set; using std::unordered_multiset; using std::multiset; using std::bitset; using std::priority_queue; /* Initial processing */ struct Preprocessing { Preprocessing() { std::cin.tie(0); std::ios::sync_with_stdio(0); }; }_Preprocessing; /* Remove the source of the bug */ auto pow(signed, signed) { assert(false); } /* define hash */ namespace std { template <> class hash> { public: size_t operator()(const std::pair& x) const { return hash()(1000000000 * x.first + x.second); } }; } /* input */ template std::istream& operator >> (std::istream& is, vector& vec) { for(T& x : vec) is >> x; return is; } /* constant value */ constexpr ll MOD = 1000000007; // constexpr ll MOD = 998244353; //============================================================================================= signed main() { ll h, w; cin >> h >> w; VVL a; a.reserve(h); REP(_, h) { VL v(w); cin >> v; a.emplace_back(v); } VVVL dp(2, VVL(h, VL(w))); REP(k, 2) { dp[k][0][0] = a[0][0]; } auto update = [&](ll y, ll x, ll k, ll val) { if(y < 0 || x < 0 || y >= h || x >= w) { return; } if(val <= a[y][x]) { if(k < 1 && !(y == h - 1 && x == w - 1)) { chmax(dp[k + 1][y][x], val); } return; } chmax(dp[k][y][x], val + a[y][x]); }; REP(i, h)REP(j, w) REP(k, 2) { update(i + 1, j, k, dp[k][i][j]); update(i, j + 1, k, dp[k][i][j]); } dump(dp); cout << ((dp[1][h - 1][w - 1] == 0) ? "No" : "Yes") << endl; }