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: #
  # abc061 c
  #
  import sys
  from io import StringIO
  import unittest
  
  
  class TestClass(unittest.TestCase):
      def assertIO(self, input, output):
          stdout, stdin = sys.stdout, sys.stdin
          sys.stdout, sys.stdin = StringIO(), StringIO(input)
          resolve()
          sys.stdout.seek(0)
          out = sys.stdout.read()[:-1]
          sys.stdout, sys.stdin = stdout, stdin
          self.assertEqual(out, output)
  
      def test_入力例_1(self):
          input = """3 4
  1 1
  2 2
  3 3"""
          output = """3"""
          self.assertIO(input, output)
  
      def test_入力例_2(self):
          input = """10 500000
  1 100000
  1 100000
  1 100000
  1 100000
  1 100000
  100000 100000
  100000 100000
  100000 100000
  100000 100000
  100000 100000"""
          output = """1"""
          self.assertIO(input, output)
  
  
  def resolve():
      N, K = map(int, input().split())
      D = [list(map(int, input().split())) for _ in range(N)]
  
      t = 0
      for d in D:
          t += d[1]
          if t >= K:
              print(d[0])
              break
  
  
  if __name__ == "__main__":
      # unittest.main()
      resolve()
  
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"}]