Buggy python submission (verdict: Runtime Error):
import sys
#import numpy as np

stdin = sys.stdin

ri = lambda: int(rs())
rl = lambda: list(map(int, stdin.readline().split())) # applies to numbers only
rs = lambda: stdin.readline().rstrip()  # ignore trailing spaces

N = ri()
A = [ri() for _ in range(N)]
x_to_i = {x:i for i, x in enumerate(sorted(A))}
rank = [x_to_i[x] for x in A]
answer = sum((i^x)&1 for i,x in enumerate(rank)) // 2
print(B)


Fixed submission:
import sys
import numpy as np

stdin = sys.stdin

ri = lambda: int(rs())
rl = lambda: list(map(int, stdin.readline().split())) # applies to numbers only
rs = lambda: stdin.readline().rstrip()  # ignore trailing spaces

N = ri()
A = [ri() for _ in range(N)]
B = sorted(A)
B = set(B[1::2])
C = [i%2==1 and a not in B for i, a in enumerate(A)]
print(sum(C))

Buggy python submission (verdict: Time Limit Exceeded):
import sys
import numpy as np

stdin = sys.stdin

ri = lambda: int(rs())
rl = lambda: list(map(int, stdin.readline().split())) # applies to numbers only
rs = lambda: stdin.readline().rstrip()  # ignore trailing spaces

N = ri()
A = [ri() for _ in range(N)]
B = np.array(sorted(A))
C = [np.where(B == a)[0][0] for a in A]
answer = sum([i%2==1 and x%2!=1 for i, x in enumerate(C)])
print(answer)
# 41


Fixed submission:
import sys
import numpy as np

stdin = sys.stdin

ri = lambda: int(rs())
rl = lambda: list(map(int, stdin.readline().split())) # applies to numbers only
rs = lambda: stdin.readline().rstrip()  # ignore trailing spaces

N = ri()
A = [ri() for _ in range(N)]
B = sorted(A)
B = set(B[1::2])
C = [i%2==1 and a not in B for i, a in enumerate(A)]
print(sum(C))

Buggy python submission (verdict: Runtime Error):
import sys
import numpy as np

stdin = sys.stdin

ri = lambda: int(rs())
rl = lambda: list(map(int, stdin.readline().split())) # applies to numbers only
rs = lambda: stdin.readline().rstrip()  # ignore trailing spaces

N = ri()
A = [ri() for _ in range(N)]
B = sorted(np.array(A))
C = [np.where(B == a)[0][0] for a in A]
answer = sum([i%2==1 and x%2!=1 for i, x in enumerate(C)])
print(answer)
# 41


Fixed submission:
import sys
import numpy as np

stdin = sys.stdin

ri = lambda: int(rs())
rl = lambda: list(map(int, stdin.readline().split())) # applies to numbers only
rs = lambda: stdin.readline().rstrip()  # ignore trailing spaces

N = ri()
A = [ri() for _ in range(N)]
B = sorted(A)
B = set(B[1::2])
C = [i%2==1 and a not in B for i, a in enumerate(A)]
print(sum(C))

Buggy python submission (verdict: Time Limit Exceeded):
import sys
import numpy as np

stdin = sys.stdin

ri = lambda: int(rs())
rl = lambda: list(map(int, stdin.readline().split())) # applies to numbers only
rs = lambda: stdin.readline().rstrip()  # ignore trailing spaces

N = ri()
A = np.array([ri() for _ in range(N)])
B = sorted(A)
C = [np.where(B == a)[0][0] for a in A]
answer = sum([i%2==1 and x%2!=1 for i, x in enumerate(C)])
print(answer)
# 41

Fixed submission:
import sys
import numpy as np

stdin = sys.stdin

ri = lambda: int(rs())
rl = lambda: list(map(int, stdin.readline().split())) # applies to numbers only
rs = lambda: stdin.readline().rstrip()  # ignore trailing spaces

N = ri()
A = [ri() for _ in range(N)]
B = sorted(A)
B = set(B[1::2])
C = [i%2==1 and a not in B for i, a in enumerate(A)]
print(sum(C))