#include <stdio.h>

int main()
{
    int a, b, v, w, t;

    scanf("%d %d", &a, &v);
    scanf("%d %d", &b, &w);
    scanf("%d", &t);

    if (a > b)
    {
        int tmp;
        tmp = a;
        a = b;
        b = tmp;
    }

    for (int i = 0; i <= t; i++)
    {
        a += v * i;
        b += w * i;
        if (a >= b)
        {
            printf("YES");
            return 0;
        }
    }

    printf("NO");
    return 0;
}
