#include<bits/stdc++.h>
using namespace std ;
#define int long long
string smallestString(string s) {
int n = s.size();
if(s[0]=='a'){
string x ="";
x.push_back(s[0]);
int i=1;
while(s[i]!='a'&& i<n){
int t= s[i];
char m = char(t-1);
x.push_back(m);
i++;
}
if(n-(i)>0 and i< n ){
string t= s.substr(i,n-(i));
x+=t;
}
return x ;
}
else {
string x ="";
int i=0;
while(s[i]!='a'&& i<n){
int t= s[i];
char m = (t-1);
x.push_back(m);
}
if(n-(i) >0 and i<n){
string t= s.substr(i,n-(i));
x+=t;
}
return x ;
}
}
int32_t main(){
string s ;
cin>>s ;
cout<< smallestString(s);
return 0;
}