import sys
input = sys.stdin.readline
N, M = map(int, input().split())
lst = [0]
lst.extend(list(map(int, input().split())))
for i in range(N+1):
lst[i] = lst[i-1] + lst[i]
for _ in range(M):
I, J = map(int, input().split())
print(lst[J] - lst[I-1])