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

a='maerd'
b='esare'
c='resare'
d='remaerd'
s_rev=''

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

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

count=0
do while (count<=s_len)
if(index(s_rev,a)==1)then
count=count+len(a)
s_rev=s_rev(len(a)+1:)

else if(index(s_rev,b)==1)then
count=count+len(b)
s_rev=s_rev(len(b)+1:)

else if(index(s_rev,c)==1)then
count=count+len(c)
s_rev=s_rev(len(c)+1:)

else if(index(s_rev,d)==1)then
count=count+len(d)
s_rev=s_rev(len(d)+1:)

else
write(*,*) 'NO'
goto 100
endif
end do

write(*,*) 'YES'

100 end





write(e(,*)