func_code_string: #include <bits/stdc++.h>   using namespace std;   FILE *stm;   const double PI = 22.0 / 7.0;   const long long MXN = 1e5 + 1;   const long long MNN = 1e3 + 1;   const long long MOD = 1e9 + 7;   const long long INF = 1e18;   bool srt(string a, string b) { return a.size() > b.size(); }   int gcd(int a, int b) {     if (b == 0)       return a;     else       gcd(b, a % b);   }   int lcm(int a, int b) { return (b / gcd(a, b)) * a; }   int main() {     string first;     cin >> first;     int n = first.size();     int ctr = 0;     int j = 0;     while (first[j] ==  a  and j < n) {       ctr++;       j++;     }     if (ctr == n) {       first[n - 1] =  z ;     } else if (first[0] !=  a ) {       for (int i = 0; i < n and first[i] !=  a ; i++) first[i] = first[i] - 1;     } else if (first[0] ==  a ) {       int i = 0;       while (first[i] ==  a ) {         i++;       }       for (; i < n and first[i] !=  a ; i++) first[i] = first[i] - 1;     }     cout << first << endl;     return 0;   }   