'求1000以内既是回文数又是素数的数
FOR i=11 TO 999
j = INT(SQR(I))
flag = 0
FOR k%=2 TO j
if i MOD k%=0 THEN
flag = 1
EXIT FOR
END IF
NEXT k%
IF flag=0 THEN
a$ = STR$(I)
b$ = LTRIM$(a$)
n = LEN(b$)
FOR l=1 TO INT(n/2)
c$ = MID$(b$, L, 1)
d$ = MID$(b$, n - L + 1, 1)
IF c$<>d$ THEN
flag = 1
EXIT FOR
END IF
NEXT l
END IF
IF flag=0 THEN PRINT i
NEXT i
END
