import java.util.scanner;
public class Main {
private static int N = 100010; // 定义数组大小, 防止越界
public static void main(String[] args) {
// 初始化输入值
Scanner in = new Scanner(System.in);
int n = in.nextInt();
int m = in.nextInt();
int[] arr = new int[N];
// 注意这里是从 1开始的
for (int i = 1; i <= n; i++)
arr[i] = in.nextInt();
// s[i]代表 arr的前 i项和
int s[] = new int[N];
s[0] = 0;
for (int i = 1; i <= n; i++)
s[i] = s[i - 1] + arr[i];
while (m-- > 0) {
int l = in.nextInt();
int r = in.nextInt();
System.out.println(s[r] - s[l - 1]);
}
}
}