Can you suggest what is causing this error.

N = int(input())
s = [0]

for i in range(N):
   k = int(input())
   s.append(int(s[i] + k))

Q = int(input())
while Q:
   l, r = map(int, input().split())
   print(s[r] - s[l-1])
   Q -= 1