func_code_string: #include <bits/stdc++.h>   using namespace std;   long long power(long long base, long long exp) {     long long res = 1;     while (exp > 0) {       if (exp % 2 == 1) res = (res * base);       base = (base * base);       exp /= 2;     }     return res;   }   long long mod(long long a, long long b) { return (a % b + b) % b; }   long long powerm(long long base, long long exp, long long mod) {     long long ans = 1;     while (exp) {       if (exp & 1) ans = (ans * base) % mod;       exp >>= 1, base = (base * base) % mod;     }     return ans;   }   struct custom_hash {     static uint64_t splitmix64(uint64_t x) {       x += 0x9e3779b97f4a7c15;       x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;       x = (x ^ (x >> 27)) * 0x94d049bb133111eb;       return x ^ (x >> 31);     }     size_t operator()(uint64_t x) const {       static const uint64_t FIXED_RANDOM =           chrono::steady_clock::now().time_since_epoch().count();       return splitmix64(x + FIXED_RANDOM);     }   };   int main() {     std::ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     ;     long long t;     t = 1;     while (t--) {       string s;       cin >> s;       cout << s;       for (long long i = s.size() - 1; i >= 0; i--) cout << s[i];       cout <<   n ;     }     return 0;   }   