import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;

/**
 * @author iceewei
 * @Description: 前缀和
 * @date 2025/1/17
 */
public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StreamTokenizer st = new StreamTokenizer(br);
        st.nextToken();
        int n = (int)st.nval;
        st.nextToken();
        int m = (int)st.nval;
        int[] q = new int[n + 1];
        for (int i = 1; i <= n; i++) {
            st.nextToken();
            q[i] = (int)st.nval;
        }
        int[] s = new int[n + 1];
        for (int i = 1; i <= n; i++) {
            s[i] = s[i - 1] + q[i];
        }
        while (m-- > 0) {
            st.nextToken();
            int l = (int)st.nval;
            st.nextToken();
            int r = (int)st.nval;
            System.out.println(s[r] - s[l - 1]);
        }
    }
}