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

const int MAXN = 6e5 + 5, mod = 998244353;
int T, inv[MAXN], jc[MAXN], n, m, id[MAXN], ans[MAXN], last = 1, l, r, inv_2;
struct Node {
	int x, y, pos;
}ls[MAXN];

int KSM(int a, int b) {
	int sum = 1;
	while (b) {
		if (b & 1) sum *= a, sum %= mod;
		a *= a, a %= mod;
		b >>= 1;
	}
	return sum;
}

void ycl() {
	jc[0] = inv[0] = 1;
	for (int i = 1; i <= MAXN - 5; i++) jc[i] = jc[i - 1] * i % mod, inv[i] = KSM(jc[i], mod - 2);
}

int C(int a, int b) {
	return jc[a] * inv[b] % mod * inv[a - b] % mod;
}

void MKFK() {
	int kc = cbrt(MAXN);
	for (int i = 0; i <= MAXN - 5; i++) id[i] = (i - 1) / kc + 1;
}

bool cmp(Node x, Node y) {
	if (id[x.x] != id[y.x]) return id[x.x] < id[y.x];
	return x.y < y.y;
}

void add(int x, int op) {
//	if (op) cout << l << ' ' << r << ';';
	if (op == 0) last = (last * 2 % mod - C(l, r) + mod) % mod;
	else last = (last + C(l, r + 1)) % mod;
}

void del(int x, int op) {
	if (op == 0) last = ((last + C(l, r)) % mod * inv_2) % mod;
	else last = (last - C(l, r) + mod) % mod;
}

signed main() {
	ios::sync_with_stdio(false); cin.tie(0);
	ycl();
	inv_2 = KSM(2, mod - 2);
	cin >> T;
	for (int i = 1; i <= T; i++) {
		cin >> ls[i].x >> ls[i].y;
		ls[i].x --, ls[i].y --;
		ls[i].pos = i;
	}
	MKFK();
	sort(ls + 1, ls + 1 + T, cmp);
	for (int i = 1; i <= T; i++) {
		while (l < ls[i].x) add(l, 0), l++;
//		cout << last << ' ';
		while (l > ls[i].x) del(l, 0), l--;
//		l = ls[i].x;
		while (r < ls[i].y) add(r, 1), r++;
		while (r > ls[i].y) del(r, 1), r--;
		ans[ls[i].pos] = (KSM(2, ls[i].x + 1) - 1) * last % mod;
	}
	for (int i = 1; i <= T; i++) {
		cout << ans[i] << '\n';
	}
	return 0;
}
/*
C(n, 0) + C(n, 1) + C(n, 2) + C(n, 3) + ... + C(n, m)
C(n + 1, 0) + C(n + 1, 1) + C(n + 1, 2) + C(n + 1, 3) + ... + C(n + 1, m)
= C(n, 0) + (C(n, 0) + C(n, 1)) + (C(n, 1) + C(n, 2)) + ... + (C(n, m - 1) + C(n, m))
= 2 * last - C(n, m)

1
10 9

C(4, 0) + C(4, 1)

30
91 78
78 13
9178 918
7891 787
34568 2311
91 78
78 13
9178 918
7891 787
34568 2311
91 78
78 13
9178 918
7891 787
34568 2311
91 78
78 13
9178 918
7891 787
34568 2311
91 78
78 13
9178 918
7891 787
34568 2311
91 78
78 13
9178 918
7891 787
34568 2311
*/