00007

卡码网 58 前缀和

class Solution:
    def process(self):
            n = int(input())
            nums = []
            su = 0
            for i in range(n):
                num = int(input())
                su += num
                nums.append( su)
            while True:
                try:
                    a, b = map(int, input().split())
                    if a == 0:
                        out = nums[b]
                    else:
                        out = nums[b] - nums[a - 1]
                    print(out)
                except EOFError:
                    break
if __name__ == "__main__":
    solution = Solution()
    solution.process()