因为：
FRTZZ is the code for ESSAY
E + 1 = F
S - 1 = R
S + 1 = T
A - 1 = Z
Y + 1 = Z
所以
PAPER
P+1=Q
A-1=Z
P+1=Q
E-1=D
R+1=S
答案:QZQDS