func_code_string: #include <bits/stdc++.h>   template <typename T>   struct ScanfSpecifier {};   template <>   struct ScanfSpecifier<char*> {     static constexpr const char* value =  %s ;   };   template <>   struct ScanfSpecifier<int> {     static constexpr const char* value =  %d ;   };   template <>   struct ScanfSpecifier<double> {     static constexpr const char* value =  %lf ;   };   template <>   struct ScanfSpecifier<float> {     static constexpr const char* value =  %f ;   };   template <>   struct ScanfSpecifier<char> {     static constexpr const char* value =  %c ;   };   template <>   struct ScanfSpecifier<const char*> {     static constexpr const char* value =  %s ;   };   template <>   struct ScanfSpecifier<unsigned long> {     static constexpr const char* value =  %lu ;   };   template <>   struct ScanfSpecifier<unsigned int> {     static constexpr const char* value =  %u ;   };   template <>   struct ScanfSpecifier<long long int> {     static constexpr const char* value =  %lld ;   };   template <typename T>   int RD(T& arg) {     return std::scanf(ScanfSpecifier<T>::value, &arg);   }   template <int S>   int RD(char (&arg)[S]) {     return std::scanf( %s , arg);   }   int RD(char* arg) { return std::scanf( %s , arg); }   template <>   int RD<char>(char& arg) {     return std::scanf(  %c , &arg);   }   template <typename T, typename... Args>   int RD(T& arg1, Args&... args) {     return RD(arg1) + RD(args...);   }   template <typename T>   T RD() {     T ret;     RD(ret);     return ret;   }   template <typename It>   void RDV(It begin, It end) {     while (begin != end) RD(*begin++);   }   template <typename C>   void RDV(C& c) {     RDV(std::begin(c), std::end(c));   }   template <typename T>   void WT(T arg) {     std::printf(ScanfSpecifier<T>::value, arg);   }   template <typename T, typename U>   void WT(std::pair<T, U> arg) {     std::printf( ( );     WT(arg.first);     std::printf( ,  );     WT(arg.second);     std::printf( ) );   }   template <typename... Args>   void WT(Args... args) {     int alc = 0;     int dummy[] = {((alc++ ? std::printf(   ) : 0), WT(args), 0)...};   }   template <typename... Args>   void WTL(Args... args) {     WT(args...);     std::printf(  n );   }   template <typename It>   void WTV(It begin, It end) {     int alc = 0;     while (begin != end) (alc++ ? std::printf(   ) : 0), WT(*begin++);   }   template <typename C>   void WTV(const C& c) {     WTV(std::begin(c), std::end(c));   }   template <typename It>   void WTVL(It begin, It end) {     WTV(begin, end);     std::printf(  n );   }   template <typename C>   void WTVL(const C& c) {     WTVL(std::begin(c), std::end(c));   }   struct Range {     struct It {       int num, step;       int operator*() { return num; }       void operator++() { num += step; }       bool operator!=(const It& other) { return num != other.num; }     };     Range(int ee) : b(0), e(ee) {}     Range(int bb, int ee) : b(bb), e(ee) {}     It begin() { return {b, (b < e ? 1 : -1)}; }     It end() { return {e, 0}; }     int b, e;   };   template <typename T>   inline T& UMAX(T& x, T y) {     if (x < y) x = y;     return x;   }   template <typename T>   inline T& UMIN(T& x, T y) {     if (y < x) x = y;     return x;   }   template <typename T, typename... Args>   struct ArithmiticPromotion {     typedef decltype(T() + typename ArithmiticPromotion<Args...>::type()) type;   };   template <typename T, typename U>   struct ArithmiticPromotion<T, U> {     typedef decltype(T() + U()) type;   };   template <typename T>   struct ArithmiticPromotion<T, T> {};   template <typename T>   struct ArithmiticPromotion<T> {};   template <typename T, typename U>   typename ArithmiticPromotion<T, U>::T MAX(T a, U b) {     return a < b ? b : a;   }   template <typename T, typename... Args>   typename ArithmiticPromotion<T, Args...>::T MAX(T a, Args... args) {     return MAX(a, MAX(args...));   }   template <typename T, typename U>   typename ArithmiticPromotion<T, U>::T MIN(T a, U b) {     return a < b ? a : b;   }   template <typename T, typename... Args>   typename ArithmiticPromotion<T, Args...>::T MIN(T a, Args... args) {     return MIN(a, MIN(args...));   }   using RG = Range;   using namespace std;   char L[32], R[32];   void pad(char* s) {     int l = strlen(s);     reverse(s, s + l);     for (int i : RG(l, 19)) s[i] =  0 ;     reverse(s, s + 19);     for (int i : RG(19)) s[i] -=  0 ;   }   long long int ans;   int num[10];   void dfs(int pos, int r, int total) {     if (pos < 10) {       for (int i = 0; i <= r; i++) {         num[pos] = i;         dfs(pos + 1, r - i, total + i);       }     } else {       {         bool check = true;         int use = 0;         bool b = false;         int tmp[10] = {};         int mn = 1;         for (int i = 0; i < 19; i++) {           while (mn < 10 && tmp[mn] == num[mn]) mn++;           if (!b) {             for (int d = L[i] + 1; d < R[i]; d++)               if ((!d || tmp[d] + 1 <= num[d]) && use + 19 - i - !d >= total) {                 ans++;                 return;               }           } else if (R[i]) {             if (use + 19 - i - 1 >= total ||                 (mn < R[i] && use + 19 - i >= total)) {               ans++;               return;             }           }           if (R[i]) {             ++use;             if (++tmp[R[i]] > num[R[i]]) {               check = false;               break;             }           }           if (L[i] < R[i]) b = true;         }         if (check && use == total) {           ans++;           return;         }       }       {         bool check = true;         int use = 0;         bool b = false;         int tmp[10] = {};         int mx = 9;         for (int i = 0; i < 19; i++) {           while (mx > 0 && tmp[mx] == num[mx]) mx--;           if (!b) {             for (int d = L[i] + 1; d < R[i]; d++)               if (tmp[d] + 1 <= num[d] && use + 19 - i - !d >= total) {                 ans++;                 return;               }           } else {             if (mx > L[i] && use + 19 - i >= total) {               ans++;               return;             }           }           if (L[i]) {             ++use;             if (++tmp[L[i]] > num[L[i]]) {               check = false;               break;             }           }           if (L[i] < R[i]) b = true;         }         if (check && use == total) {           ans++;           return;         }       }     }   }   int main() {     RD(L, R);     pad(L), pad(R);     dfs(1, 18, 0);     WTL(ans);   }   