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

typedef unsigned long long ull;
typedef long long ll;

const int md = 998244353;

inline int add(int x, int y) {
	if (x + y >= md) return x + y - md;
	return x + y;
}

inline int sub(int x, int y) {
	if (x < y) return x - y + md;
	return x - y;
}

inline int mul(int x, int y) {
	return 1ull * x * y % md;
}

inline int fpow(int x, int y) {
	int ans = 1;
	while (y) {
		if (y & 1) ans = mul(ans, x);
		y >>= 1; x = mul(x, x);
	}
	return ans;
}

const int M = 1e6;

unordered_map <ull, int> dp;
int inv[20], T;
ull s, t;

int solve(ull n) {
	if (n > t) return 0;
	if (dp.count(n)) return dp[n];
	vector <int> cnt(10, 0);
	ull x = n;
	int all = 0;
	while (x) {
		++cnt[x % 10];
		x /= 10; ++all;
	}
	/*
	all = 0;
	for (int i = 0; i < 9; i++) {
		if (cnt[i]) cnt[i] = 1;
		all += cnt[i];
	}
	*/
	int ans = 0;
	for (int i = 1; i < 10; i++) {
		if (cnt[i]) {
			// fprintf(stderr, "n = %llu, %d %d %d %d %d\n", n, i, cnt[i], all, mul(cnt[i], inv[all]), ans);
			ans = add(ans, mul(solve(n * (i + 1)) + 1, mul(cnt[i], inv[all])));
		}
	}
	ans = mul(ans, mul(all, inv[all - cnt[0]]));
	fprintf(stderr, "dp[%llu] = %d\n", n, ans);
	return dp[n] = ans;
}

int main() {
	for (int i = 1; i <= 19; i++) inv[i] = fpow(i, md - 2);
	cin >> T;
	while (T--) {
		cin >> s >> t;
		dp.clear();
		printf("%d\n", solve(s));
	}
	return 0;
}