#include <stdio.h>

int main(void){
    long long int A,V,B,W,T=0;
    scanf("%lld %lld %lld %lld %lld",&A,&V,&B,&W,&T);
    if(A+V*T>=B+W*T){
        printf("YES");
    }else{
        printf("NO");
    }
}