"use strict"
function main(arg) {
    let tmp = arg.trim().split("\n")
    let [A,V] = tmp[0].split(" ").map(Number)
    let [B,W] = tmp[1].split(" ").map(Number)
    let T = Number(tmp[2]) - 1
    let at = BigInt(A) + BigInt(V) * BigInt(T)
    let bw = BigInt(B) + BigInt(W) * BigInt(T)
    if (at >= bw) {
        console.log('YES')
    } else {
        console.log('NO')
    }
    // console.log([at,bw])
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));
