#include<iostream>
#include<cstring>
using namespace std;
string m="",k,c;
int t;
int main()
{
    cin >> k >> c;
    while(k.size()<c.size())
      k=k+k;
    for(int i=0;i<=c.size()-1;i++)
    {
      if('A'<=k[i]&&'Z'>=k[i]) t=k[i]-'A';
      if('a'<=k[i]&&'z'>=k[i]) t=k[i]-'a';
      if('A'<=c[i]&&'Z'>=c[i]) m+=((char)(c[i]-'A'-t+26)%26+'A');
      if('a'<=c[i]&&'z'>=c[i]) m+=((char)(c[i]-'a'-t+26)%26+'a');
    }
    cout << m;
    return 0;
}
/**************************************************************
	Problem: 2314
	User: admin
	Language: C++
	Result: Accepted
	Time:47 ms
	Memory:2076 kb
****************************************************************/