func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long INF = 1e18;   const int mod = 1e9 + 7;   const int N = 1e5 + 10;   inline int add(int x, int y) {     x += y;     if (x >= mod) x -= mod;     return x;   }   inline int mul(int x, int y) {     x = (1LL * x * y) % mod;     return x;   }   int main() {     string s;     cin >> s;     string a =  abcdefghijklmnopqrstuvwxyz ;     long long k = 0;     for (int i = 0; i <= s.size() - 1; ++i) {       if (s[i] <= a[k]) {         s[i] = a[k];         k++;       }     }     if (k == 26) {       cout << s;     } else {       cout << -1;     }   }   