#[allow(unused_imports)]
use proconio::{
    input,
    marker::{Bytes, Chars, Usize1},
};
fn main() {
    input! {
        a: usize,
        b: usize,
        c: usize,
        d: usize,
        s: usize,
    }
    let res = if a * c + b * d <= s { "Yes" } else { "No" };
    println!("{}", res);
}