output_description: Print the K-th smallest integer in the array after the N operations.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N K
      a_1 b_1
      :  
      a_N b_N
attempt: table = input().split()
  N, K = int(table[0]), int(table[1])
  preA, preB = [], []
  l = 1
  while l <= N:
      a = input().split()
      a = list(map(int, a))
      if sum(preB) < K:
          preA += [a[0]]
          preB += [a[1]]
      l += 1
  print(preA[-1])
  
problem_description: Statement
  
  There is an empty array. The following N operations will be performed to
  insert integers into the array. In the i-th operation (1≤i≤N), b_i copies of
  an integer a_i are inserted into the array. Find the K-th smallest integer in
  the array after the N operations. For example, the 4-th smallest integer in
  the array \\{1,2,2,3,3,3\\} is 3.
samples: [{"input": "3 4\n    1 1\n    2 2\n    3 3", "output": "3\n    \n\nThe resulting array is the same as the one in the problem statement.\n\n* * *"}, {"input": "10 500000\n    1 100000\n    1 100000\n    1 100000\n    1 100000\n    1 100000\n    100000 100000\n    100000 100000\n    100000 100000\n    100000 100000\n    100000 100000", "output": "1"}]