On the math lesson a teacher asked each pupil to come up with his own lucky numbers. As a fan of number theory Peter chose prime numbers. Bob was more original. He said that number *t* is his lucky number, if it can be represented as: 

Now, the boys decided to find out how many days of the interval [*l*, *r*] (*l* ≤ *r*) are suitable for pair programming. They decided that the day *i* (*l* ≤ *i* ≤ *r*) is suitable for pair programming if and only if the number *i* is lucky for Peter and lucky for Bob at the same time. Help the boys to find the number of such days.
The first line of the input contains integer numbers *l*, *r* (1 ≤ *l*, *r* ≤ 3·10<sup class="upper-index">8</sup>).
import math
l,r = map(int,input().split())
cnt = 0

n = int(1e4) + 5
m = [1] * (n+1)
for i in range(3,n,2):
    if i*i>n: break
    if m[i]: continue
    for j in range(i*i, n, i): m[j]=1

primes = [3]
for i in range(3,n,2): 
    if m[i]: primes.append(i)

for i in range(1,r):
    if i * i> r: break
    for j in range(i+1,r):
        num = (i * i) + (j * j)
        if num > r: break
        if num<l or num % 4 != 1: continue
        prime = True
        for k in primes:
            if k * k > num: break
            if num%k==0: prime = False
        if(prime): cnt+=1
if l<3 and r>2: cnt+=1
print(cnt)
  	  	 	     	   			