#include<bits/stdc++.h>
using namespace std;
string m,c,k;
int len1,len2,s;
int main(){
cin>>k>>c;
len1=k.size();
len2=c.size();
for(int i=len1;i<=len2;i++)
k[i]=k[i-len1];
for(int i=0;i<len2;i++){
if(k[i]<=90)s=k[i]-65;
else s=k[i]-97;
if(c[i]>=97){if(c[i]-s>=97)m[i]=char(c[i]-s);
else m[i]=char(123-(s-c[i]+97));
}
if(c[i]<=90){if(c[i]-s>=65)m[i]=char(c[i]-s);
else m[i]=char(91-(s-c[i]+65));
}
}
for(int i=0;i<len2;i++)
cout<<m[i];
return 0;
}