回文素数

low,high=map(int,input().split())
print(len(tuple(0 for i in \
          (2,3,5,7,11,101,131,151,181,191,313,353,373,383,727,757,787,797,919,929) \
          if low<=i<=high))) 

low,high=map(int,input().split())
res=0
for i in range(low,high+1):
    if str(i)[0]!=str(i)[-1] or i==1:
        continue
    t=True
    for j in range(2,i):
        if i%j==0:
            t=False
            break
    if t:
        res+=1
print (res)

def eladuosai(n):
    l = list(range(1, n+1))
    l[0] = 0
    for i in range(2, n+1):
        if l[i-1] !=  0 :
            for j in range(i*2, n+1, i):
                l[j-1] = 0
    result = [x for x in l if x != 0]
    return result
L, R = map(int, input().split())
num = 0
prim = eladuosai(R)
for i in range(len(prim)):
    if prim[i] >= L and str(prim[i]) == str(prim[i])[::-1]:
        num += 1
print(num)

python解法

import math

# 判断n是否为回文数且为素数
def is_prime_and_palindrome(n):
    if str(n) != str(n)[::-1]:
        return False
    if n <= 1:
        return False
    for i in range(2, int(math.sqrt(n)) + 1):
        if n % i == 0:
            return False
    return True

start, end = map(int, input().split())
print(len(list(filter(lambda c: is_prime_and_palindrome(c), range(start, end + 1)))))

sushu_list = []
# inp = [int(x) for x in input().split()]
# L = inp[0]
# R = inp[1]
L, R = [int(x) for x in input().split()]
for i in range(L,R+1):
    sym = 0
    for j in range(2,int(i**0.5)+1):
        if i%j == 0 :
            sym = 1
            break
    if sym == 0:
        sushu_list.append(i)
if 1 in sushu_list:
    sushu_list.pop(0)

sum = 0
sushu_list = [str(x) for x in sushu_list]
for x in sushu_list:
    if x == x[::-1]:
        sum += 1

print(sum)

# coding=utf-8

# 判断一个数是否为素数
def Prime_number(n):
    if n%2 == 0 :
        return False
    else:
        for i in range(3,n,2):
            if n%i == 0:
                return False
        return True

# 判断一个数是否为回文数
def Palindrome(n):
    if str(n) == str(n)[::-1]:
        return True
    else:
        return False

def fun():
    s = map(int,raw_input().split())
    L,R = s[0],s[1]
    count = 0
    for i in range(L,R+1):
        if Prime_number(i) and Palindrome(i):
            count += 1
    return count

if __name__=='__main__':
    print(fun())