func_code_string: #include <bits/stdc++.h>   using namespace std;   int f(long long p) {     int ans = 0;     while (p) {       ans += p % 10;       p /= 10;     }     return ans;   }   long long g(long long a) {     if (a == 0) return 0;     int digit = 0;     long long b = a;     while (b >= 10) {       digit++;       b /= 10;     }     int b_digit = b;     long long ans = b * digit;     for (int i = 0; i < digit; i++) ans *= 10, b *= 10;     ans *= 9;     ans /= 2;     for (int i = 0; i < b_digit; i++) ans += i * (b / b_digit);     ans += g(a - b) + b_digit * (a - b + 1);     return ans;   }   int main() {     long long a;     scanf( %lld , &a);     long long l = 1, r = 20000000000000000LL;     while (l < r) {       long long mid = (l + r) / 2;       if (g(mid) >= a)         r = mid;       else         l = mid + 1;     }     l = 1;     long long cur = g(r);     while (cur != a) {       if (cur > a) {         cur -= f(l);         l++;       } else {         cur += f(r + 1);         r++;       }     }     printf( %lld %lld , l, r);   }   