
function main(input) {
  let args = input.split('\n');
  let x = 0;
  let [a, v] = args[x++].split(' ');
  let [b, w] = args[x++].split(' ');
  if (+a > +b) {
    console.log('YES');
    return;
  }
  let t = BigInt(args[x++]);
  let maxA = BigInt(a) + BigInt(v) * t;
  let maxB = BigInt(b) + BigInt(w) * t;
  console.log(maxA < maxB ? 'YES' : 'NO');
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));