#include <iostream>
#include <vector>

constexpr int mod = 998244353;

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

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

    std::vector<int> last(n);
    for (int i = 1; i < n; i++) {
        if (a[i] > a[i - 1]) {
            last[i] = last[i - 1];
        } else {
            last[i] = i;
        }
    }

    const int64_t half = (mod + 1) / 2;

    std::vector<int64_t> s(n + 1), pow_half(n + 1);
    int64_t mul = 1;
    pow_half[0] = 1;
    for (int i = 0; i < n; i++) {
        s[i + 1] = (s[i] + mul * a[i]) % mod;
        mul += mul;
        if (mul >= mod) mul -= mod;
        pow_half[i + 1] = pow_half[i] * half % mod;
    }

    for (int i = 0; i < q; i++) {
        int l, r;
        std::cin >> l >> r;
        l--;
        r--;
        l = std::max(l, last[r]);
        std::cout << ((s[r + 1] - s[l + 1]) * pow_half[l + 1] + a[l]) % mod
                  << '\n';
    }

    return 0;
}