#include <iostream>

using namespace std;

const int N = 100010;

int n, m;
int q[N], s[N]; // s[0] 初始化为 0 ; 为后续的s[i] = s[i - 1] + q[i] 做准备

int main()
{
    cin >> n >> m;

    for (int i = 1; i <= n; i ++ ) scanf("%d", &q[i]), s[i] = s[i - 1] + q[i];//读入数组，并初始化前缀和数组
    //算前缀和数组，或者差分数组，从下标1开始更加省事优雅。记得初始化好前缀和s[0] = 0。
    //从0开始需要特判s[0] = q[0]

    while (m -- )
    {
        int l, r;
        scanf("%d%d", &l, &r);
        printf("%d\n", s[r] - s[l - 1]);
    }
    return 0;
}