use std::fs;

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

fn main() {
    let s = fs::read_to_string("/dev/stdin").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 a: Vec<i64> = vec![0; n];
    for i in 0..n {
        a[i] = v[i + 2].trim().parse().unwrap();
    }
    let mut l: Vec<usize> = vec![0; q];
    let mut r: Vec<usize> = vec![0; q];
    for i in 0..q {
        l[i] = v[2 * i + n + 2].trim().parse().unwrap();
        r[i] = v[2 * i + n + 3].trim().parse().unwrap();
    }

    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 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;
    }

    for i in 0..q {
        l[i] -= 1;
        r[i] -= 1;
        l[i] = l[i].max(last[r[i]]);
        println!(
            "{}",
            ((a_sum[r[i] + 1] - a_sum[l[i] + 1] + MOD) * pow_half[l[i] + 1] + a[l[i]]) % MOD
        );
    }
}