XDU Problem 1063 - Enjoy It

#include<cstdio>
#include<iostream>
#include<cstring>
using namespace std;
int main()
{
	//freopen("data.txt","r",stdin);
	//freopen("out.txt","w",stdout);
	char s[100000];
	while(gets(s))
	{
		for(int i=0;;i++)
		{
			char c=s[i];
			if(c=='\0') 
			{
				cout<<endl;
				break;
			}
			if((c>='a'&&c<='z')||(c>='A'&&c<='Z'))
			{
				char b=c-10;
				if(c>='a'&&c<='z'&&c-'a'<10) b='z'-10+c-'a'+1;
				if(c>='A'&&c<='Z'&&c-'A'<10) b='Z'-10+c-'A'+1;
				cout<<b;
			}
			else
			{
				cout<<c;
			}
		}
	}
	return 0;
}