Xor sum

buffer = input().split()
n = int(buffer[0])
q = int(buffer[1])
values = list(map(int,input().split()))

xorsums = []
for j in range(n):
    res = values[j]
    for i in range(a,b):
        res = res ^ values[i]
    xorsums.append(res)

for _ in range(q):
    query = input().split()
    a = int(query[0]) - 1
    b = int(query[1]) - 1

    print(xorsums[b] - xorsums[a])

Test 1

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 9, in <module>
    for i in range(a,b):
NameError: name 'a' is not defined

Test 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 9, in <module>
    for i in range(a,b):
NameError: name 'a' is not defined