Buggy python submission (verdict: Runtime Error):
import itertools
import math
import string
import collections
from collections import Counter
from collections import deque
from operator import itemgetter
import sys
sys.setrecursionlimit(2*10**5)
INF = 2**60


def readints():
    return list(map(int, input().split()))


def nCr(n, r):
    return math.factorial(n)//(math.factorial(n-r)*math.factorial(r))


def has_duplicates2(seq):
    seen = []
    for item in seq:
        if not(item in seen):
            seen.append(item)
    return len(seq) != len(seen)


def divisor(n):
    divisor = []
    for i in range(1, n+1):
        if n % i == 0:
            divisor.append(i)
    return divisor


# coordinates
dx = [-1, -1, -1, 0, 0, 1, 1, 1]
dy = [-1, 0, 1, -1, 1, -1, 0, 1]

n, k = map(int, input().split())
ab = [readints() for _ in range(n)]
# print(ab)
abab = sorted(ab)
# print(abab)
tmp = 0
for i in range(n):
    tmp += ab[i][1]
    if tmp >= k:
        print(ab[tmp-k][0])
        break


Fixed submission:
import itertools
import math
import string
import collections
from collections import Counter
from collections import deque
from operator import itemgetter
import sys
sys.setrecursionlimit(2*10**5)
INF = 2**60


def readints():
    return list(map(int, input().split()))


def nCr(n, r):
    return math.factorial(n)//(math.factorial(n-r)*math.factorial(r))


def has_duplicates2(seq):
    seen = []
    for item in seq:
        if not(item in seen):
            seen.append(item)
    return len(seq) != len(seen)


def divisor(n):
    divisor = []
    for i in range(1, n+1):
        if n % i == 0:
            divisor.append(i)
    return divisor


# coordinates
dx = [-1, -1, -1, 0, 0, 1, 1, 1]
dy = [-1, 0, 1, -1, 1, -1, 0, 1]

n, k = map(int, input().split())
ab = [readints() for _ in range(n)]
# print(ab)
abab = sorted(ab)
# print(abab)
tmp = 0
for i in range(n):
    tmp += abab[i][1]
    if tmp >= k:
        print(abab[i][0])
        break

Buggy python submission (verdict: Runtime Error):
import itertools
import math
import string
import collections
from collections import Counter
from collections import deque
from operator import itemgetter
import sys
sys.setrecursionlimit(2*10**5)
INF = 2**60


def readints():
    return list(map(int, input().split()))


def nCr(n, r):
    return math.factorial(n)//(math.factorial(n-r)*math.factorial(r))


def has_duplicates2(seq):
    seen = []
    for item in seq:
        if not(item in seen):
            seen.append(item)
    return len(seq) != len(seen)


def divisor(n):
    divisor = []
    for i in range(1, n+1):
        if n % i == 0:
            divisor.append(i)
    return divisor


# coordinates
dx = [-1, -1, -1, 0, 0, 1, 1, 1]
dy = [-1, 0, 1, -1, 1, -1, 0, 1]

n, k = map(int, input().split())
ab = [readints() for _ in range(n)]
# print(ab)
abab = sorted(ab)
# print(abab)
tmp = 0
for i in range(n):
    tmp += ab[i][1]
    if tmp >= k:
        print(ab[tmp-k][0])
        exit()


Fixed submission:
import itertools
import math
import string
import collections
from collections import Counter
from collections import deque
from operator import itemgetter
import sys
sys.setrecursionlimit(2*10**5)
INF = 2**60


def readints():
    return list(map(int, input().split()))


def nCr(n, r):
    return math.factorial(n)//(math.factorial(n-r)*math.factorial(r))


def has_duplicates2(seq):
    seen = []
    for item in seq:
        if not(item in seen):
            seen.append(item)
    return len(seq) != len(seen)


def divisor(n):
    divisor = []
    for i in range(1, n+1):
        if n % i == 0:
            divisor.append(i)
    return divisor


# coordinates
dx = [-1, -1, -1, 0, 0, 1, 1, 1]
dy = [-1, 0, 1, -1, 1, -1, 0, 1]

n, k = map(int, input().split())
ab = [readints() for _ in range(n)]
# print(ab)
abab = sorted(ab)
# print(abab)
tmp = 0
for i in range(n):
    tmp += abab[i][1]
    if tmp >= k:
        print(abab[i][0])
        break

Buggy python submission (verdict: Time Limit Exceeded):
import itertools
import math
import string
import collections
from collections import Counter
from collections import deque
from operator import itemgetter
import sys
sys.setrecursionlimit(2*10**5)
INF = 2**60


def readints():
    return list(map(int, input().split()))


def nCr(n, r):
    return math.factorial(n)//(math.factorial(n-r)*math.factorial(r))


def has_duplicates2(seq):
    seen = []
    for item in seq:
        if not(item in seen):
            seen.append(item)
    return len(seq) != len(seen)


def divisor(n):
    divisor = []
    for i in range(1, n+1):
        if n % i == 0:
            divisor.append(i)
    return divisor


# coordinates
dx = [-1, -1, -1, 0, 0, 1, 1, 1]
dy = [-1, 0, 1, -1, 1, -1, 0, 1]

n, k = map(int, input().split())
ans = []
for i in range(n):
    a, b = readints()
    for j in range(b):
        ans.append(a)
aannss = sorted(ans)
print(aannss[k-1])


Fixed submission:
import itertools
import math
import string
import collections
from collections import Counter
from collections import deque
from operator import itemgetter
import sys
sys.setrecursionlimit(2*10**5)
INF = 2**60


def readints():
    return list(map(int, input().split()))


def nCr(n, r):
    return math.factorial(n)//(math.factorial(n-r)*math.factorial(r))


def has_duplicates2(seq):
    seen = []
    for item in seq:
        if not(item in seen):
            seen.append(item)
    return len(seq) != len(seen)


def divisor(n):
    divisor = []
    for i in range(1, n+1):
        if n % i == 0:
            divisor.append(i)
    return divisor


# coordinates
dx = [-1, -1, -1, 0, 0, 1, 1, 1]
dy = [-1, 0, 1, -1, 1, -1, 0, 1]

n, k = map(int, input().split())
ab = [readints() for _ in range(n)]
# print(ab)
abab = sorted(ab)
# print(abab)
tmp = 0
for i in range(n):
    tmp += abab[i][1]
    if tmp >= k:
        print(abab[i][0])
        break