function main(input) {
  let args = input.split('\n');
  let x = 0;
  let [a, v] = args[x++].split(' ');
  let [b, w] = args[x++].split(' ');
  let t = +args[x++];

  let maxA = +a + +v * t;
  let maxB = +b + +w * t;
  console.log(maxA < maxB ? 'NO' : 'YES');
}

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