Alice is exploring the wonderland, suddenly she fell into a hole, when she woke up, she found there are b - a + 1 treasures labled a from b in front of her.
Alice was very excited but unfortunately not all of the treasures are real, some are fake.
Now we know a treasure labled n is real if and only if [n/1] + [n/2] + ... + [n/k] + ... is even.
Now given 2 integers a and b, your job is to calculate how many real treasures are there.
Input
The input contains multiple cases, each case contains two integers a and b (0 <= a <= b <= 263-1) seperated by a single space. Proceed to the end of file.
Output
Output the total number of real treasure.
Sample Input
0 2 0 10
Sample Output
1 6
1 #include<iostream> 2 #include<stdio.h> 3 #include<cstring> 4 #include<cstdlib> 5 #include<math.h> 6 using namespace std; 7 typedef unsigned long long LL; 8 9 LL solve(LL n) 10 { 11 LL m = (LL)sqrt(n*1.0); 12 LL sum=0; 13 if(m%2==0) sum = n-m*m; 14 if(m%2==1) m++; 15 LL j=m/2; 16 sum=sum-j+2*j*j; 17 // sum=sum+2*j*j-j; 18 return sum; 19 } 20 int main() 21 { 22 LL n,m; 23 while(scanf("%llu%llu",&n,&m)>0) 24 { 25 n++,m++; 26 LL ans=solve(n-1); 27 LL cur =solve(m); 28 printf("%llu ",cur-ans); 29 } 30 return 0; 31 }