//Author: Kevin
#include<bits/stdc++.h>
//#pragma GCC optimize("O2")
using namespace std;
#define ll long long
#define ull unsigned ll
#define pb emplace_back
#define mp make_pair
#define ALL(x) (x).begin(),(x).end()
#define rALL(x) (x).rbegin(),(x).rend()
#define srt(x) sort(ALL(x))
#define rev(x) reverse(ALL(x))
#define rsrt(x) sort(rALL(x))
#define sz(x) (int)(x.size())
#define inf 0x3f3f3f3f
#define pii pair<int,int>
#define lb(v,x) (int)(lower_bound(ALL(v),x)-v.begin())
#define ub(v,x) (int)(upper_bound(ALL(v),x)-v.begin())
#define uni(v) v.resize(unique(ALL(v))-v.begin())
#define longer __int128_t
void die(string S){puts(S.c_str());exit(0);}
ll val[20][20];
int cnt[20][20];
long double val2[20][20];
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	for(int i=2;i<=16;i++)
		for(int j=1;j<i;j++)
		{
			val[i][j]=j;
			cnt[i][j]=1;
			val2[i][j]=log10(j);
		}
	vector<ll> value;
	while(sz(value)<1000000)
	{
		int ax=2,ay=1;
		for(int i=2;i<=16;i++)
			for(int j=1;j<i;j++)
				if(val2[i][j]<val2[ax][ay])
				{
					ax=i;
					ay=j;
				}
		value.pb(val[ax][ay]);
		ll tmp2=val[ax][ay];
		for(int i=2;i<=16;i++)
			for(int j=1;j<i;j++)
				if(tmp2==val[i][j])
				{
					cnt[i][j]++;
					val[i][j]=(val[i][j]*i+j)%998244353;
					val2[i][j]=log10(i)*cnt[i][j]+log10(j)-log10(i-1);
				}
	}
	vector<ll> psum;
	psum.pb(0);
	for(auto x:value)
		psum.pb((psum.back()+x)%998244353);
	int t;
	cin>>t;
	while(t--)
	{
		int l,r;
		cin>>l>>r;
		cout<<(psum[r]-psum[l-1]+998244353)%998244353<<'\n';
	}
	return 0;
}