思路应该是对的，但是后两个点错了。

#include <bits/stdc++.h>
#define int long long
using namespace std;

const int mod = 998244353;

int n, q;

int spow(int a, int b)
{
	int ans = 1, base = a;
	while(b > 0)
    {
		if(b & 1) ans = ans * base % mod;
        base = base * base % mod;
		b >>= 1LL;
	}
	return ans % mod;
}

int slog(int a)
{
	if (a == 0)
	{
		return n;
	}
	int cnt = 0;
	while (a % 2 == 0)
	{
		cnt ++;
		a /= 2;
	}
	return cnt;
}

signed main()
{
	scanf("%lld %lld", &n, &q);
	while (q --)
	{
		int x, y;
		scanf("%lld %lld", &x, &y);
		x ++;
		x = (int)ceil(x / (spow(2, y) * 1.0)) % mod;
		if(y > 64)
		{
			cout << spow(2, n) - 1 << "\n";
			continue;
		}
		for (int i = 1; i <= y; i ++)
		{
			if (x % 2 == 0)
			{
				x = x * 2 % mod;
			}
			else
			{
				x = x * 2 % mod, x --;
			}
		}
		if (x % 2 == 0)
		{
			printf("%lld\n", spow(2, slog(x)) - 1);
		}
		else if (x % 2 == 1)
		{
			printf("%lld\n", spow(2, slog(x - 1)) - 1);
		}
	}
	return 0;
}