#include<iostream>

#include<cstdlib>

#include<cstdio>

#include<cmath>

#include<cstring>

#include<iomanip>

#include<algorithm>

#include<ctime>

#include<queue>

#include<stack>

#define rg register

#define lst long long

#define N 1050

using namespace std;

int lmy,lmw,now=-;

char my[N],mw[N],ans[N];

inline int read()

{

    rg int s=,m=;rg char ch=getchar();

    while(ch!='-'&&(ch<''||ch>''))ch=getchar();

    if(ch=='-')m=-,ch=getchar();

    while(ch>=''&&ch<='')s=(s<<)+(s<<)+ch-'',ch=getchar();

    return s*m;

}

int main()

{

    cin>>my>>mw;

//    puts(my),puts(mw);

    lmy=strlen(my),lmw=strlen(mw);

//    cout<<lmy<<" "<<lmw<<endl;

    for(rg int i=;i<lmy;++i)

        if(my[i]>='a'&&my[i]<='z')my[i]-=;

//    puts(my);

    for(rg int i=;i<lmw;++i)

    {

        now++;

        if(now==lmy)now=;

        ans[i]=mw[i]-my[now]+'A';

        if(ans[i]<'a'&&(mw[i]>='a'&&mw[i]<='z'))ans[i]=mw[i]-my[now]+'A'+;

        if(ans[i]<'A'&&(mw[i]>='A'&&mw[i]<='Z'))ans[i]=mw[i]-my[now]+'A'+;

    }

    puts(ans);

    return ;

}