:: `
def calculator(n, m, li):
print("Your list: ", li)
for i in range(0, n//m):
z1 = sum(li[0 + i*m : (i+1)*m])
x.append(z1)
if n%m != 0:
z2 = sum(li[(n//m)*m : ])
x.append(z2)
print("list of summations: ", x)
z3 = len(x)
res = 0
for i in range(0, z3):
res += ((-1)**i) * x[i]
print("List's final value: ", res)
flag = True
while(flag):
x = []
n = int(input("Enter n: "))
m = int(input("Enter m: "))
li = list(map(int, input("Enter your list numbers separated by space: ").split()))
if n < 2: print("n (lenght of list) must be at least 2. Try again! ") flag = False elif m >= n:
print("m must be less than n. Try again!")
flag = False
elif len(li) != n:
print("Please enter exactly ", n, " elements for your list, separated by 1 space. Try again!")
flag = False
else:
calculator(n, m, li)
if flag == True:
resp = input("Do you want to continue (Yes or No)?: ")
if resp.upper() == "NO" or resp.upper() == "N":
flag = False
`
