#pragma comment(linker, "/stack:200000000") #pragma GCC optimize("Ofast") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") // need #include #include // data structure #include #include #include #include #include #include #include #include #include //#include #include #include #include #include // stream //#include #include //#include #include // etc #include #include #include #include #include #include #include // input #define INIT std::ios::sync_with_stdio(false);std::cin.tie(0); #define VAR(type, ...)type __VA_ARGS__;MACRO_VAR_Scan(__VA_ARGS__); template void MACRO_VAR_Scan(T& t) { std::cin >> t; } templatevoid MACRO_VAR_Scan(First& first, Rest&...rest) { std::cin >> first; MACRO_VAR_Scan(rest...); } #define VEC_ROW(type, n, ...)std::vector __VA_ARGS__;MACRO_VEC_ROW_Init(n, __VA_ARGS__); for(int w_=0; w_ void MACRO_VEC_ROW_Init(int n, T& t) { t.resize(n); } templatevoid MACRO_VEC_ROW_Init(int n, First& first, Rest&...rest) { first.resize(n); MACRO_VEC_ROW_Init(n, rest...); } template void MACRO_VEC_ROW_Scan(int p, T& t) { std::cin >> t[p]; } templatevoid MACRO_VEC_ROW_Scan(int p, First& first, Rest&...rest) { std::cin >> first[p]; MACRO_VEC_ROW_Scan(p, rest...); } #define VEC(type, c, n) std::vector c(n);for(auto& i:c)std::cin>>i; #define MAT(type, c, m, n) std::vector> c(m, std::vector(n));for(auto& R:c)for(auto& w:R)std::cin>>w; // output #define OUT(dist) std::cout<<(dist); #define FOUT(n, dist) std::cout<=(a);--w) #define REP(w, n) for(int w=0;w=0;--w) #define FORLL(w, a, n) for(ll w=ll(a);w=ll(a);--w) #define REPLL(w, n) for(ll w=0;w=0;--w) #define IN(a, x, b) (a<=x && x inline T CHMAX(T& a, const T b) { return a = (a < b) ? b : a; } template inline T CHMIN(T& a, const T b) { return a = (a > b) ? b : a; } #define EXCEPTION(msg) throw std::string("Exception : " msg " [ in ") + __func__ + " : " + std::to_string(__LINE__) + " lines ]" #define TRY(cond, msg) try {if (cond) EXCEPTION(msg);}catch (std::string s) {std::cerr << s << std::endl;} //void CHECKTIME(std::function f) { auto start = std::chrono::system_clock::now(); f(); auto end = std::chrono::system_clock::now(); auto res = std::chrono::duration_cast((end - start)).count(); std::cerr << "[Time:" << res << "ns (" << res / (1.0e9) << "s)]\n"; } // test template using V = std::vector; template using VV = V>; template std::ostream& operator<<(std::ostream& os, std::pair p) { os << "(" << p.first << ", " << p.second << ")"; return os; } #define random_shuffle "USE std::shuffle!"; // type/const #define int ll using ll = long long; using ull = unsigned long long; using ld = long double; using PAIR = std::pair; using PAIRLL = std::pair; constexpr int INFINT = 1 << 30; // 1.07x10^ 9 constexpr int INFINT_LIM = (1LL << 31) - 1; // 2.15x10^ 9 constexpr ll INFLL = 1LL << 60; // 1.15x10^18 constexpr ll INFLL_LIM = (1LL << 62) - 1 + (1LL << 62); // 9.22x10^18 constexpr double EPS = 1e-6; constexpr int MOD = 1000000007; constexpr double PI = 3.141592653589793238462643383279; template void FILL(T(&a)[N], const T& val) { for (auto& x : a) x = val; } template void FILL(ARY(&a)[N][M], const T& val) { for (auto& b : a) FILL(b, val); } template void FILL(std::vector& a, const T& val) { for (auto& x : a) x = val; } template void FILL(std::vector>& a, const T& val) { for (auto& b : a) FILL(b, val); } // ------------>8------------------------------------->8------------ int calc(int n, int l, V x, V y) { std::set a, b; REP(i, n) a.insert(x[i]), b.insert(y[i]); int ans = 0; int now = *a.begin(); ans += now; while (!a.empty()) { if (a.size() == 1) { int a0 = *a.begin(); int b0 = *b.begin(); ans += (b0 - a0) + (a0 > b0 ? l : 0); break; } auto it = b.upper_bound(now); if (it == b.end()) it = b.begin(); int t = *it; auto it2 = a.upper_bound(t); if (it2 == a.end()) it2 = a.begin(); int t2 = *it2; auto it3 = b.lower_bound(t2); int t3 = -1; if (it3 == b.begin()) t3 = *b.rbegin(); else { --it3; t3 = *it3; } ans += (t3 - now) + (now > t3 ? l : 0); if (now == t2) { ++it2; if (it2 == a.end()) it2 = a.begin(); t2 = *it2; } ans += (t2 - t3) + (t3 > t2 ? l : 0); a.erase(now); b.erase(t3); now = t2; } return ans; } signed main() { INIT; VAR(int, n, l); VEC(int, x, n); VEC(int, y, n); OUT(calc(n, l, x, y))BR; return 0; }