#pragma comment(linker, "/STACK:1024000000,1024000000")

#include<cstdio>

#include<cstring>

#include<cmath>

#include<algorithm>

#include<vector>

#include<map>

#include<set>

#include<queue>

#include<stack>

#include<iostream>

using namespace std;

typedef long long LL;

const double pi=acos(-1.0),eps=1e-;

void File()

{

    freopen("D:\\in.txt","r",stdin);

    freopen("D:\\out.txt","w",stdout);

}

template <class T>

inline void read(T &x)

{

    char c = getchar(); x = ;while(!isdigit(c)) c = getchar();

    while(isdigit(c)) { x = x *  + c - ''; c = getchar();  }

}

const int maxn=;

char s[maxn]; bool flag;

int main()

{

    scanf("%s",s);

    for(int i=;s[i];i++)

    {

        if(s[i]=='a')

        {

            if(flag==) continue;

            else break;

        }

        s[i]--; flag=;

    }

    if(flag==)

    {

        int len=strlen(s);

        s[len-]='z';

    }

    printf("%s\n",s);

    return ;

}