import std;

void main () {
    int N, S, B; readln.read(N, S, B);
    auto H = readln.split.to!(int[]);

    bool ok = true;
    foreach (i; 0..N - 1) {
        if (H[i] + 1L * S * B < H[i + 1]) ok = false;
    }

    if (ok) {
        writeln("Yes");
    }
    else {
        writeln("No");
    }
}

void read (T...) (string S, ref T args) {
    import std.conv : to;
    import std.array : split;
    auto buf = S.split;
    foreach (i, ref arg; args) {
        arg = buf[i].to!(typeof(arg));
    }
}