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
for i in range(1,r):
    if i * i> r: break
    nx = int(math.sqrt(max(0,l-i*i))) + 1
    for j in range(max(i+1, nx),r):
        num = (i * i) + (j * j)
        if num > r: break
        if num<l or num % 4 != 1: continue
        prime = True
        for k in range(3,num,2):
            if k * k > num:
                break
            if num%k==0: 
                prime = False
                break
        if(prime): cnt+=1
if l<3: cnt+=1
print(cnt)
  	 	   		 		 	 		 	 	 	 		 	 	