Problem 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.

Input

Output

Print the K-th smallest integer in the array after the N operations.

Constraints

• 1≤N≤10^5
• 1≤a_i,b_i≤10^5
• 1≤K≤b_1…+…b_n
• All input values are integers.

Sample Input 1

3 4
1 1
2 2
3 3

Sample Output 1

3

The resulting array is the same as the one in the problem statement.

Sample Input 2

10 500000
1 100000
1 100000
1 100000
1 100000
1 100000
100000 100000
100000 100000
100000 100000
100000 100000
100000 100000

Sample Output 2

1

见题面 Input 部分

见题面 Output 部分