题解

#include<bits/stdc++.h>
using namespace std;
void Aa(string &x){
	for(int i=0;i<x.size();i++){
	if(x[i]>='A'&&x[i]<='Z')x[i]+=32;
	else if(x[i]>='a'&&x[i]<='z')x[i]-=32;
	}
}
int main(){
	string s;
	cin>>s;
	int len=s.size();
	for(int i=0;i<s.size();i++){
		s[i]+=3;
		if(s[i]>'z')s[i]-=26;
		else if(s[i]<='a'&&s[i]>'Z')s[i]-=26;
	}
	reverse(s.begin(),s.end());
	Aa(s);
	cout<<s;
	return 0;
}