#include<stdio.h>
typedef long long ll;
int main(void)
{
  ll a,b,v,w,t;
  scanf("%lld %lld %lld %lld %lld",&a,&v,&b,&w,&t);
  if((a+v*t)>=(b+w*t)){
    puts("YES");
  }else{
    puts("NO");
  }
  return 0;
}
