output_description: Print the number of possible pairs that he may have had.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N K
attempt: # a%b >= K iff xb+K <= a < (x+1)b
  # bごとに数えるだけ
  
  N,K = map(int,input().split())
  ans = 0
  
  for b in range(K+1,N+1):
    cnt = 0
    x_max = N//b
    # 0 <= x < x_max
    # 各xに対してb-K個ある
    cnt += x_max * (b-K)
    # x = x_max
    lower = x_max*b+K
    if lower <= N:
  	upper = min((x_max+1)*b-1,N)
      cnt += upper - lower + 1
    ans += cnt
    
  print(ans)
problem_description: Statement
  
  Takahashi had a pair of two positive integers not exceeding N, (a,b), which he
  has forgotten. He remembers that the remainder of a divided by b was greater
  than or equal to K. Find the number of possible pairs that he may have had.
samples: [{"input": "5 2", "output": "7\n    \n\nThere are seven possible pairs: (2,3),(5,3),(2,4),(3,4),(2,5),(3,5) and (4,5).\n\n* * *"}, {"input": "10 0", "output": "100\n    \n\n* * *"}, {"input": "31415 9265", "output": "287927211"}]