## https://yukicoder.me/problems/no/2170

MOD = 998244353

class BinaryIndexTree:
    """
    フェニック木(BinaryIndexTree)の基本的な機能を実装したクラス
    """
    def __init__(self, size):
        self.size = size
        self.array = [0] * (size + 1)
    
    def add(self, x, a):
        index = x
        while index <= self.size:
            self.array[index] += a
            self.array[index] %= MOD
            index += index & (-index)
    
    def sum(self, x):
        index = x
        ans = 0
        while index > 0:
            ans += self.array[index]
            ans %= MOD
            index -= index & (-index)
        return ans

    def least_upper_bound(self, value):
        if self.sum(self.size) < value:
            return -1
        elif value <= 0:
            return 0

        m = 1
        while m < self.size:
            m *= 2

        k = 0
        k_sum = 0
        while m > 0:
            k0 = k + m
            if k0 < self.size:
                if k_sum + self.array[k0] < value:
                    k_sum += self.array[k0]
                    k += m
            m //= 2
        if k < self.size:
            return k + 1
        else:
            return -1

def main():
    N, Q = map(int, input().split())
    A = list(map(int, input().split()))
    lr = []
    for _ in range(Q):
        l, r = map(int, input().split())
        lr.append((l - 1, r - 1))

    # 各 r について短調減少して行き着く先を求める
    left_index = [-1] * N
    l_index = -1
    for r in range(N):
        if l_index == -1:
            l_index = r
        else:
            if A[r - 1] >= A[r]:
                l_index = r
        
        left_index[r] = l_index

    r_map = {}
    for i in range(Q):
        l, r = lr[i]
        if r not in r_map:
            r_map[r] = []
        r_map[r].append((i, l))
    
    answers = [0] * Q
    bit = BinaryIndexTree(N)
    for r in range(N):
        l_index = left_index[r]
        if l_index != r:
            x = pow(2, r - l_index - 1, MOD)
            bit.add(r + 1, (A[r] * x) % MOD)

        if r in r_map:
            for i, l in r_map[r]:
                target_l = max(l, l_index)
                x = (bit.sum(r + 1) - bit.sum(target_l + 1)) % MOD

                x *= pow(pow(2, target_l - l_index, MOD), MOD - 2, MOD)
                x %= MOD
                x += A[target_l]
                x %= MOD
                answers[i] = x

        
    for i in range(Q):
        print(answers[i])


    
    






if __name__ == "__main__":
    main()