use std::io;

const MOD: i64 = 998244353;
const HALF: i64 = (MOD + 1) / 2;

fn main() {
    let mut s = String::new();
    io::stdin().read_line(&mut s).unwrap();
    let v: Vec<_> = s.split_whitespace().collect();
    let n: usize = v[0].trim().parse().unwrap();
    let q: usize = v[1].trim().parse().unwrap();
    let mut s = String::new();
    io::stdin().read_line(&mut s).unwrap();
    let v = s.split_whitespace();
    let mut a: Vec<i64> = Vec::new();
    for x in v {
        a.push(x.trim().parse().unwrap());
    }
    let a = a;

    let mut last = vec![0; n];
    for i in 1..n {
        if a[i] > a[i - 1] {
            last[i] = last[i - 1];
        } else {
            last[i] = i;
        }
    }
    let last = last;

    let mut a_sum = vec![0; n + 1];
    let mut pow_half = vec![1; n + 1];
    let mut mul: i64 = 1;
    for i in 0..n {
        a_sum[i + 1] = (a_sum[i] + mul * a[i]) % MOD;
        mul += mul;
        if mul >= MOD {
            mul -= MOD;
        }
        pow_half[i + 1] = pow_half[i] * HALF % MOD;
    }
    let a_sum = a_sum;
    let pow_half = pow_half;

    for _ in 0..q {
        let mut s = String::new();
        io::stdin().read_line(&mut s).unwrap();
        let v: Vec<_> = s.split_whitespace().collect();
        let mut l: usize = v[0].trim().parse().unwrap();
        let mut r: usize = v[1].trim().parse().unwrap();
        l -= 1;
        r -= 1;
        l = l.max(last[r]);
        let l = l;
        let r = r;
        println!(
            "{}",
            ((a_sum[r + 1] - a_sum[l + 1]) * pow_half[l + 1] + a[l]) % MOD
        );
    }
}