#include <bits/stdc++.h>

#include <atcoder/modint>

using namespace std;
using namespace atcoder;

using mint = modint998244353;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n, q;
    cin >> n >> q;
    vector<int64_t> a(n);
    for (auto &&x : a) {
        cin >> x;
    }

    vector<int> last(n);
    for (int i = 1; i < n; i++) {
        if (a.at(i) > a.at(i - 1)) {
            last.at(i) = last.at(i - 1);
        } else {
            last.at(i) = i;
        }
    }

    const mint half = mint(1) / 2;

    vector<mint> s(n + 1), pow_half(n + 1);
    mint mul = 1;
    pow_half.at(0) = 1;
    for (int i = 0; i < n; i++) {
        s.at(i + 1) = s.at(i) + mul * a.at(i);
        mul += mul;
        pow_half.at(i + 1) = pow_half.at(i) * half;
    }

    for (int i = 0; i < q; i++) {
        int l, r;
        cin >> l >> r;
        l--;
        r--;
        l = max(l, last.at(r));
        cout << ((s.at(r + 1) - s.at(l + 1)) * pow_half.at(l + 1) + a.at(l))
                    .val()
             << '\n';
    }

    return 0;
}