implicit none
integer(8):: n,y,i,j,count,s_len
character(10**5)::s,s_rev
character(5)::a
character(5)::b
character(6)::c
character(7)::d

a="maerd"
b="esare"
c="resare"
d="remaerd"

s_rev=""

read(5,*) s
s_len=len_trim(s)

do i=1,s_len
    s_rev(s_len+1-i:s_len+1-i)=s(i:i)
enddo

count=1

do while (count<s_len)

    if (index(s_rev,a)==count) then
        count=count+5
    
    else if (index(s_rev,b)==count) then
        count=count+5
        
    else if (index(s_rev,c)==count) then
        count=count+6
        
    else if (index(s_rev,d)==count) then
        count=count+7
        
    else 
        write(6,*) "NO"
        goto 100
        
    endif

enddo

write(6,*) "YES"
 
100 end

