#include <cstdio>
#include <iostream>
#include <algorithm>
#include <map>
using namespace std;

// #define Debug

const int N = 1e5;
const long long P = 998244353;

const int Lg = 17, SZ = N * Lg * 5;
typedef pair<int, int> pir;

int n, m;
long long a[N + 5];

struct Node
{
	int ls, rs;
	pir interval;//l, r
} node[SZ + 5];
int tot;

#define ls(p) node[p].ls
#define rs(p) node[p].rs

void modify(int p, int q, int l, int r, int pos, pir inte)
{
	if (l == r)
		return node[p].interval = inte, void();

	int mid = (l + r) >> 1;
	if (pos <= mid)
	{
		ls(p) = ++tot, rs(p) = rs(q);
		modify(ls(p), ls(q), l, mid, pos, inte);
	}
	else
	{
		rs(p) = ++tot, ls(p) = ls(q);
		modify(rs(p), rs(q), mid + 1, r, pos, inte);
	}
	return ;
}
pir query(int p, int l, int r, int pos)
{
	if (l == r)
		return node[p].interval;

	int mid = (l + r) >> 1;
	if (pos <= mid)
		return query(ls(p), l, mid, pos);
	return query(rs(p), mid + 1, r, pos);
}

int rootP[N + 5], rootS[N + 5];
int szP[N + 5], szS[N + 5];
long long ansP[N + 5], ansS[N + 5];

long long sum[N + 5];//sum ai, should not mod P
long long sqr[N + 5];//sum ai^2
long long inv[N + 5];

long long calc(int l, int r)//sum (ai - ave)^2 = sum ai^2 + len * ave^2 - 2 * ave * sum ai
{
	long long ave = (sum[r] - sum[l - 1]) % P * inv[r - l + 1] % P;
	long long res = (sqr[r] - sqr[l - 1] + P) % P;
	res = (res + ave * ave % P * (r - l + 1) % P) % P;
	res = (res - ave * 2 * (sum[r] - sum[l - 1]) % P + P) % P;
	return res;
}

pir stk[N + 5];
int top;

int get_pos(int x, long long val, int R)
{
	int l = 1, r = szP[x - 1], L = 1;
	while (l <= r)
	{
		int mid = (l + r) >> 1;
		pir res = query(rootP[x - 1], 1, n, mid);
		int lb = res.first, rb = res.second;

		if ((sum[rb] - sum[lb - 1]) * (R - rb) < 
			(sum[R] - sum[rb] + val - a[x]) * (rb - lb + 1))
		{
			L = rb + 1;
			l = mid + 1;
		}
		else
			r = mid - 1;
	}
	return L;
}
long long solve(int x, long long val)
{
	int l = 1, r = szS[x + 1], R = n;//[x, x]
	while (l <= r)
	{
		int mid = (l + r) >> 1;
		
		pir res = query(rootS[x + 1], 1, n, mid);
		int lb = res.first, rb = res.second;
		int L0 = get_pos(x, val, lb - 1);

		if ((sum[rb] - sum[lb - 1]) * (lb - L0) >= 
			(sum[lb - 1] - sum[L0 - 1] + val - a[x]) * (rb - lb + 1))
		{
			R = lb - 1;
			l = mid + 1;
		}
		else
			r = mid - 1;
	}
	int L = get_pos(x, val, R);//if R = n, won't execute the while-loop

	long long newSum = (sum[R] - sum[L - 1] + val - a[x]) % P;
	long long newSqr = (sqr[R] - sqr[L - 1] + val * val % P - a[x] * a[x] % P + P * 2) % P;

	int len = R - L + 1;
	long long ave = newSum * inv[len] % P;
	
	long long res = (ansP[L - 1] + ansS[R + 1]) % P;
	res = (res + newSqr) % P;
	res = (res + ave * ave % P * len % P) % P;
	res = (res - ave * 2 * newSum % P + P) % P;
	return res;
}

int main()
{
	// freopen("sequence.in", "r", stdin);
	// freopen("sequence.out", "w", stdout);

	scanf("%d%d", &n, &m);
	for (int i = 1; i <= n; i++)
	{
		scanf("%lld", a + i);

		sum[i] = sum[i - 1] + a[i];
		sqr[i] = (sqr[i - 1] + a[i] * a[i] % P) % P;
	}

	inv[1] = 1;
	for (int i = 2; i <= n; i++)
		inv[i] = (P - P / i) * inv[P % i] % P;

	for (int i = 1; i <= n; i++)
	{
		int bound = i;
		while (top)
		{
			int l = stk[top].first, r = stk[top].second;
			if ((sum[r] - sum[l - 1]) * (i - r) >= 
				(sum[i] - sum[r]) * (r - l + 1))
			{
				bound = l;
				top--;
			}
			else
				break;
		}
		stk[++top] = make_pair(bound, i);

		int fa = stk[top - 1].second;

		rootP[i] = ++tot;
		szP[i] = szP[fa] + 1;
		ansP[i] = (ansP[fa] + calc(bound, i)) % P;

		modify(rootP[i], rootP[fa], 1, n, szP[i], stk[top]);
	}

	top = 0;
	for (int i = n; i > 0; i--)
	{
		int bound = i;
		while (top)
		{
			int l = stk[top].first, r = stk[top].second;
			if ((sum[r] - sum[l - 1]) * (l - i) <= 
				(sum[l - 1] - sum[i - 1]) * (r - l + 1))
			{
				bound = r;
				top--;
			}
			else
				break;
		}
		stk[++top] = make_pair(i, bound);

		int fa = stk[top - 1].first;

		rootS[i] = ++tot;
		szS[i] = szS[fa] + 1;
		ansS[i] = (ansS[fa] + calc(i, bound)) % P;
		
		modify(rootS[i], rootS[fa], 1, n, szS[i], stk[top]);
	}

	printf("%lld\n", ansP[n]);
	for (int i = 1; i <= m; i++)
	{
		int pos;
		long long val;
		scanf("%d%lld", &pos, &val);
		printf("%lld\n", solve(pos, val));
	}
	return 0;
}