#include using namespace std; using ll = long long; const int INF = (int)1e9 + 1001010; const ll llINF = (long long)4e18 + 22000020; const string endn = "\n"; template inline auto vector2(size_t i, size_t j, const T &init = T()) { return vector(i, vector(j, init)); } const string ELM_SEP = " ", VEC_SEP = endn; template istream &operator>>(istream &i, vector &A) { for(auto &I : A) { i >> I; } return i; } template ostream &operator<<(ostream &o, const vector &A) { int i = A.size(); for(const auto &I : A) { o << I << (--i ? ELM_SEP : ""); } return o; } template ostream &operator<<(ostream &o, const vector> &A) { int i = A.size(); for(const auto &I : A) { o << I << (--i ? VEC_SEP : ""); } return o; } template vector &operator++(vector &A, int) { for(auto &I : A) { I++; } return A; } template vector &operator--(vector &A, int) { for(auto &I : A) { I--; } return A; } template bool chmax(T &a, const U &b) { return ((a < b) ? (a = b, true) : false); } template bool chmin(T &a, const U &b) { return ((a > b) ? (a = b, true) : false); } ll floor(ll a, ll b) { if(b < 0) a = -a, b = -b; return (a >= 0) ? a / b : (a + 1) / b - 1; } ll ceil(ll a, ll b) { if(b < 0) a = -a, b = -b; return (a > 0) ? (a - 1) / b + 1 : a / b; } ll bit(unsigned long long val, unsigned long long digit) { return (val >> digit) & 1; } #ifdef DEBUG #include #define dump(...) cpp_dump(__VA_ARGS__) namespace cp = cpp_dump; struct InitCppDump { InitCppDump() { if(!isatty(fileno(stderr))) CPP_DUMP_SET_OPTION(es_style, cpp_dump::es_style_t::no_es); CPP_DUMP_SET_OPTION(log_label_func, cp::log_label::line()); CPP_DUMP_SET_OPTION(max_iteration_count, 30); } } init_cpp_dump; #else #define dump(...) #endif // ==================== ここまでテンプレ ==================== int main(int argc, char *argv[]) { ios::sync_with_stdio(false); cin.tie(nullptr); ll n, s, b; cin >> n >> s >> b; vector h(n); cin >> h; ll can_h = h[0] + s * b; for(int i = 1; i < n; i++){ if(can_h < h[i]){ cout << "No" << endn; return 0; } chmax(can_h, h[i] + s * b); } cout << "Yes" << endn; return 0; }