#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using namespace atcoder; typedef long long ll; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--) #define repk(i, k, n) for (int i = k; i < (int)(n); i++) #define all(v) v.begin(), v.end() #define mod1 1000000007 #define mod2 998244353 #define mod3 100000007 #define vi vector #define vs vector #define vc vector #define vl vector #define vb vector #define vvi vector> #define vvc vector> #define vvl vector> #define vvb vector> #define vvvi vector>> #define vvvl vector>> #define pii pair #define pil pair #define pli pair #define pll pair #define vpii vector> #define vpll vector> #define vvpii vector>> #define vvpll vector>> template void debug(T e) { cerr << e << endl; } template void debug(vector &v) { rep(i, v.size()) { cerr << v[i] << " "; } cerr << endl; } template void debug(vector> &v) { rep(i, v.size()) { rep(j, v[i].size()) { cerr << v[i][j] << " "; } cerr << endl; } } template void debug(vector> &v) { rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; } } template void debug(set &st) { for (auto itr = st.begin(); itr != st.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(multiset &ms) { for (auto itr = ms.begin(); itr != ms.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(map &mp) { for (auto itr = mp.begin(); itr != mp.end(); itr++) { cerr << itr->first << " " << itr->second << endl; } } void debug_out() { cerr << endl; } template void debug_out(Head H, Tail... T) { cerr << H << " "; debug_out(T...); } using mint = modint998244353; void debug_mint1(vector &vec) { for (int i = 0; i < vec.size(); i++) { cerr << vec[i].val() << " "; } cerr << endl; } void debug_mint2(vector> &vec) { for (int i = 0; i < vec.size(); i++) { for (int j = 0; j < vec[i].size(); j++) { cerr << vec[i][j].val() << " "; } cerr << endl; } } ll K; const mint inv_2 = mint(499122177); ll divs; mint calc(ll upper_z = -1){ mint pow_10 = mint(10).pow(K); mint all_sum = (pow_10 * inv_2 - mint(1)) * (pow_10 * inv_2); if (upper_z == -1){ return all_sum; } ll cnt = divs; cnt -= (upper_z + 1); if (cnt == 0){ return all_sum; } ll max_val = (cnt - 1) / 2; all_sum -= mint(max_val) * mint(max_val + 1); if (cnt % 2 == 0){ all_sum -= mint(max_val + 1); } return all_sum; } int main() { ll T; cin >> T; while(T--){ ll N; cin >> N >> K; divs = 1; for (ll i = 0; i < K; i++){ divs *= 10LL; } ll z_sup = N / divs; ll rem = N % divs; // debug_out(z_sup, rem); // 何通りあるかを地道に数える mint ans = mint(0); mint times = mint(z_sup / 2 - 1); mint prod_time = (times * (times + 1)); if (z_sup % 2 == 1){ prod_time += mint(z_sup / 2); } // debug(prod_time.val()); ans += prod_time * calc().val(); ans += mint(z_sup / 2) * calc(rem).val(); cout << ans.val() << endl; } }