Problem:
Score : 300 points

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.

Constraints

1≤N≤10^5

1≤a_i,b_i≤10^5

1≤K≤b_1…+…b_n

All input values are integers.

Input

Input is given from Standard Input in the following format:

N K
a_1 b_1
:
a_N b_N

Output

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

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

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt(); 
        int b = sc.nextInt();
        int c = 0;
        int ans = 0;
		int [] in1 = new int [a];
        int [] in2 = new int [a];
        int [] in3 = new int [a];
        
        for(int i=0;i<a;i++){in1[i] = sc.nextInt();
                             in2[i] = sc.nextInt();
                             in3[i] = in1[i];
                            }
		Arrays.sort(in1);       		
        while(ans==0){for(int i=0;i<a;i++){
        for(int j=0;j<a;j++){if(in1[i] == in3[j]){c+=in2[j];}
                             if(c>=b){ans=in1[i];}
                            }                                      
                            }
                     }
		System.out.println(ans);
	}
}