#include <bits/stdc++.h> using namespace std; template<typename T> void fin(T a){ cout<<a<<endl; exit(0); } signed main(){ string s;cin>>s; for(int i=0;i<s.size();i++){ int tmp=(i+1)%26; s[i]-=tmp; if(s[i]<'A')s[i]+=26; } cout<<s<<endl; }