#include <iostream>
#include <vector>

#include <atcoder/modint>

using mint = atcoder::modint998244353;

int main() {
    int n, q;
    std::cin >> n >> q;

    std::vector<long long> a(n);
    for (auto &&e : a) std::cin >> e;

    std::vector<int> inc_sum(n);
    for (int i = 0; i < n - 1; ++i) {
        inc_sum[i + 1] = inc_sum[i] + (a[i] < a[i + 1]);
    }
    std::vector<mint> a_sum(n + 1);
    for (int i = n - 1; i >= 0; --i) {
        a_sum[i] = 2 * a_sum[i + 1] + a[i];
    }
    std::vector<mint> pow_2(n + 1);
    pow_2[0] = 1;
    for (int i = 1; i <= n; ++i) {
        pow_2[i] = pow_2[i - 1] + pow_2[i - 1];
    }

    for (int qid = 0; qid < q; ++qid) {
        int l, r;
        std::cin >> l >> r;
        --l, --r;

        int ng = l - 1, ok = r;
        while (ok - ng > 1) {
            int mid = (ok + ng) >> 1;
            (inc_sum[r] - inc_sum[mid] == r - mid ? ok : ng) = mid;
        }
        std::cout << (a_sum[ok + 1] - a_sum[r + 1] * pow_2[r - ok] + a[ok]).val() << '\n';
    }
}