#include using namespace std; #define CPP_STR(x) CPP_STR_I(x) #define CPP_CAT(x, y) CPP_CAT_I(x, y) #define CPP_STR_I(args...) #args #define CPP_CAT_I(x, y) x##y #define ASSERT(expr...) assert((expr)) using i8 = int8_t; using u8 = uint8_t; using i16 = int16_t; using u16 = uint16_t; using i32 = int32_t; using u32 = uint32_t; using i64 = int64_t; using u64 = uint64_t; using f32 = float; using f64 = double; // }}} constexpr i64 INF = 1'010'000'000'000'000'017LL; constexpr i64 MOD = 998244353LL; constexpr f64 EPS = 1e-12; constexpr f64 PI = 3.14159265358979323846; #define M5 100007 #define M9 1000000000 #define F first #define S second // util {{{ #define FOR(i, start, end) for (i64 i = (start), CPP_CAT(i, xxxx_end) = (end); i < CPP_CAT(i, xxxx_end); ++i) #define REP(i, n) FOR(i, 0, n) #define all(x) (x).begin(), (x).end() #define ll long long int #define VI vector #define VVI vector #define ISD true #define debug(x) \ if (ISD) \ cout << #x << ": " << x << endl template > bool chmax(T &xmax, const U &x, Comp comp = {}) { if (comp(xmax, x)) { xmax = x; return true; } return false; } template > bool chmin(T &xmin, const U &x, Comp comp = {}) { if (comp(x, xmin)) { xmin = x; return true; } return false; } int main() { ll N, S, B; cin >> N >> S >> B; vector H(N); REP(i, N) cin >> H[i]; ll c = H[0]; REP(i, N - 1) { if (c < H[i + 1] && H[i] + S * B < H[i + 1]) { cout << "No" << endl; return 0; } chmax(c, H[i] + S * B); } cout << "Yes" << endl; }