Buggy python submission (verdict: Time Limit Exceeded):
import math
import copy
from copy import deepcopy
import sys
import fractions
# import numpy as np
from functools import reduce
# import statistics
import heapq
import collections
import itertools
sys.setrecursionlimit(100001)

# input = sys.stdin.readline
# sys.setrecursionlimit(10**6)

# ===FUNCTION===

def getInputInt():
    inputNum = int(input())
    return inputNum


def getInputListInt():
    outputData = []
    inputData = input().split()
    outputData = [int(n) for n in inputData]

    return outputData


def getSomeInputInt(n):
    outputDataList = []
    for i in range(n):
        inputData = int(input())
        outputDataList.append(inputData)

    return outputDataList


def getSomeInputListInt(n):
    inputDataList = []
    outputDataList = []
    for i in range(n):
        inputData = input().split()
        inputDataList = [int(n) for n in inputData]
        outputDataList.append(inputDataList)

    return outputDataList


# ===CODE===

n, k = map(int, input().split())

data = []
input_data = input().split()
data = [int(n) for n in input_data]
data_exp = []
for d in data:
    data_exp.append(1 + (d-1)/2)

ans = 0
for i in range(0, n-k+1, 1):
    exp_val = 0
    for j in range(k):
        exp_val += data_exp[i+j]
    ans = max(ans, exp_val)

print(ans)




Fixed submission:
import math
import copy
from copy import deepcopy
import sys
import fractions
# import numpy as np
from functools import reduce
# import statistics
import heapq
import collections
import itertools
sys.setrecursionlimit(100001)

# input = sys.stdin.readline
# sys.setrecursionlimit(10**6)

# ===FUNCTION===

def getInputInt():
    inputNum = int(input())
    return inputNum


def getInputListInt():
    outputData = []
    inputData = input().split()
    outputData = [int(n) for n in inputData]

    return outputData


def getSomeInputInt(n):
    outputDataList = []
    for i in range(n):
        inputData = int(input())
        outputDataList.append(inputData)

    return outputDataList


def getSomeInputListInt(n):
    inputDataList = []
    outputDataList = []
    for i in range(n):
        inputData = input().split()
        inputDataList = [int(n) for n in inputData]
        outputDataList.append(inputDataList)

    return outputDataList


# ===CODE===

n, k = map(int, input().split())

data = []
input_data = input().split()
data = [int(n) for n in input_data]

data_exp = [0]
for i in range(n):
    data_exp.append(data_exp[i] + 1 + (data[i]-1)/2)

ans = 0
for i in range(n-k+1):
    tmp_ans = data_exp[i+k] - data_exp[i]
    ans = max(ans, tmp_ans)

print(ans)

Buggy python submission (verdict: Runtime Error):
import math
import copy
from copy import deepcopy
import sys
import fractions
# import numpy as np
from functools import reduce
# import statistics
import heapq
import collections
import itertools
sys.setrecursionlimit(100001)

# input = sys.stdin.readline
# sys.setrecursionlimit(10**6)

# ===FUNCTION===

def getInputInt():
    inputNum = int(input())
    return inputNum


def getInputListInt():
    outputData = []
    inputData = input().split()
    outputData = [int(n) for n in inputData]

    return outputData


def getSomeInputInt(n):
    outputDataList = []
    for i in range(n):
        inputData = int(input())
        outputDataList.append(inputData)

    return outputDataList


def getSomeInputListInt(n):
    inputDataList = []
    outputDataList = []
    for i in range(n):
        inputData = input().split()
        inputDataList = [int(n) for n in inputData]
        outputDataList.append(inputDataList)

    return outputDataList


# ===CODE===

n, k = map(int, input().split())

data = []
input_data = input().split()
data = [int(n) for n in input_data]
data_exp = []
for d in data:
    data_exp.append(1 + (d-1)/2)

ans = 0
for i in range(0, n-k+1, 1):
    exp_val = 0
    for j in range(k):
        exp_val += data_exp[i+k]
    ans = max(ans, exp_val)

print(ans)




Fixed submission:
import math
import copy
from copy import deepcopy
import sys
import fractions
# import numpy as np
from functools import reduce
# import statistics
import heapq
import collections
import itertools
sys.setrecursionlimit(100001)

# input = sys.stdin.readline
# sys.setrecursionlimit(10**6)

# ===FUNCTION===

def getInputInt():
    inputNum = int(input())
    return inputNum


def getInputListInt():
    outputData = []
    inputData = input().split()
    outputData = [int(n) for n in inputData]

    return outputData


def getSomeInputInt(n):
    outputDataList = []
    for i in range(n):
        inputData = int(input())
        outputDataList.append(inputData)

    return outputDataList


def getSomeInputListInt(n):
    inputDataList = []
    outputDataList = []
    for i in range(n):
        inputData = input().split()
        inputDataList = [int(n) for n in inputData]
        outputDataList.append(inputDataList)

    return outputDataList


# ===CODE===

n, k = map(int, input().split())

data = []
input_data = input().split()
data = [int(n) for n in input_data]

data_exp = [0]
for i in range(n):
    data_exp.append(data_exp[i] + 1 + (data[i]-1)/2)

ans = 0
for i in range(n-k+1):
    tmp_ans = data_exp[i+k] - data_exp[i]
    ans = max(ans, tmp_ans)

print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import math
import copy
from copy import deepcopy
import sys
import fractions
# import numpy as np
from functools import reduce
# import statistics
import heapq
import collections
import itertools
sys.setrecursionlimit(100001)

# input = sys.stdin.readline
# sys.setrecursionlimit(10**6)

# ===FUNCTION===

def getInputInt():
    inputNum = int(input())
    return inputNum


def getInputListInt():
    outputData = []
    inputData = input().split()
    outputData = [int(n) for n in inputData]

    return outputData


def getSomeInputInt(n):
    outputDataList = []
    for i in range(n):
        inputData = int(input())
        outputDataList.append(inputData)

    return outputDataList


def getSomeInputListInt(n):
    inputDataList = []
    outputDataList = []
    for i in range(n):
        inputData = input().split()
        inputDataList = [int(n) for n in inputData]
        outputDataList.append(inputDataList)

    return outputDataList


# ===CODE===

n, k = map(int, input().split())

data = []
input_data = input().split()
data = [int(n) for n in input_data]

ans = 0
for i in range(0, n-k+1, 1):
    exp_val = 0
    for j in range(k):
        exp_val += 1 + (data[i+j]-1)/2
    ans = max(ans, exp_val)

print(ans)




Fixed submission:
import math
import copy
from copy import deepcopy
import sys
import fractions
# import numpy as np
from functools import reduce
# import statistics
import heapq
import collections
import itertools
sys.setrecursionlimit(100001)

# input = sys.stdin.readline
# sys.setrecursionlimit(10**6)

# ===FUNCTION===

def getInputInt():
    inputNum = int(input())
    return inputNum


def getInputListInt():
    outputData = []
    inputData = input().split()
    outputData = [int(n) for n in inputData]

    return outputData


def getSomeInputInt(n):
    outputDataList = []
    for i in range(n):
        inputData = int(input())
        outputDataList.append(inputData)

    return outputDataList


def getSomeInputListInt(n):
    inputDataList = []
    outputDataList = []
    for i in range(n):
        inputData = input().split()
        inputDataList = [int(n) for n in inputData]
        outputDataList.append(inputDataList)

    return outputDataList


# ===CODE===

n, k = map(int, input().split())

data = []
input_data = input().split()
data = [int(n) for n in input_data]

data_exp = [0]
for i in range(n):
    data_exp.append(data_exp[i] + 1 + (data[i]-1)/2)

ans = 0
for i in range(n-k+1):
    tmp_ans = data_exp[i+k] - data_exp[i]
    ans = max(ans, tmp_ans)

print(ans)