package main

import "fmt"

func Query(s []int, l, r int) int {
    return s[r] - s[l-1]
}

func main() {
    var n, m int
    fmt.Scanf("%d %d", &n, &m)

    num, sums := 0, make([]int, n+1)
    for i := 1; i <= n; i++ {
        fmt.Scanf("%d", &num)
        sums[i] = sums[i-1] + num
    }

    for i := 0; i < m; i++ {
        var l, r int
        fmt.Scanf("%d %d", &l, &r)
        fmt.Println(Query(sums, l, r))
    }
}