#include <bits/stdc++.h>
using namespace std;
#define IO ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
typedef long long ll;
const long long N = 3e5 + 7, Mod = 998244353, INF = 2e18;
ll inv(ll a, ll b = Mod) { return 1 < a ? b - inv(b % a, a) * b / a : 1; }
const int dx[9] = {0, 0, 1, -1, 1, 1, -1, -1, 0};
const int dy[9] = {1, -1, 0, 0, -1, 1, 1, -1, 0};
string sl, sr;
ll dp[N][2][2][11];
ll sol(int x, int gr, int ls, int prv)
{
    if (x == sr.size())
        return 1;
    ll &ret = dp[x][gr][ls][prv];
    if (~ret)
        return ret;
    int l = 0, r = 0;
    if (gr)
        l = 0;
    else
        l = sl[x] - '0';
    if (ls)
        r = 9;
    else
        r = sr[x] - '0';
    ret = 0;
    for (int i = l; i <= r; i++)
    {
        if (i == prv)
            continue;
        ll cur = sol(x + 1, gr | (i > l), ls | (i < r), i) % Mod;
        ret = ((ret % Mod + cur % Mod) % Mod + Mod) % Mod;
    }
    return ret;
}
void solve()
{
    cin >> sl >> sr;
    string tmp;
    for (int i = 0; i < sr.size() - sl.size(); i++)
        tmp.push_back('0');
    sl = tmp + sl;
    memset(dp, -1, sizeof(dp));
    cout << sol(0, 0, 0, 10) << endl;
}
int main()
{
    IO;
    int TC = 1;
    // cin >> TC;
    while (TC--)
        solve();
}