package main 

import "fmt"

const N = 100010
var n, m int 

func main () {
    a := make([]int, N)
    s := make([]int, N)
    fmt.Scanf("%d%d", &n, &m)
    for i := 1; i <= n; i ++ {
        fmt.Scanf("%d",&a[i])
    }
    for i := 1; i <= n; i ++ {
        s[i] = s[i-1] + a[i]
    }
    for ; m >0; m -- {
        var l, r int 
        fmt.Scanf("%d%d", &l, &r)
        fmt.Println(s[r]-s[l-1])
    } 
}