题解 | #【模板】静态区间和（前缀和）#Python3

n, q = map(int, input().split())
# 错开a[0]这个位置
a = [0]
a.extend(list(map(int, input().split())))
b = a.copy()
# 构造前缀和数列
for i in  range(1, n+1):
    b[i] = b[i-1] + a[i]

for _ in range(0, q):
    l, r = map(int, input().split())
    print(b[r]-b[l-1])