Written test: Niu Niu number pair problem python

# encoding=utf-8
 '''
 Niu Niu got a positive integer pair (x, y) from the teacher before, Niu Niu forgot how many they were.
But Niu Niu remembers that the teacher told him that neither x nor y is greater than n, and the remainder of dividing x by y is greater than or equal to k .
Niu Niu wants you to help him calculate how many possible pairs there are.
The input consists of two positive integers n,k(1 <= n <= 10^5, 0 <= k <= n - 1) .
Output description :
 For each test case , output a positive integer representing the number of possible pairs.
Example 1
 Input 5 2
 Output 7
 Description The number pairs that
satisfy the conditions are (2,3),(2,4),(2,5),(3,4),(3,5),(4,5), (5,3)
 '''
 if __name__ == '__main__' :



    str = raw_input()
    ls = [int(n) for n in str.split()]
    n = ls [ 0 ]
    k = ls [ 1 ]
    res = 0
for y in range(max(k, 1), n + 1):
    
        res += n/y*(y - k)
        if n % y >= k:
            if k:
                res + = n% y - k + 1
 else :            
                res += n % and
    print res