Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		n := io.NextInt()
		if n == 0 {
			break
		}
		k := make([]int, n)
		for i := 0; i < n; i++ {
			k[i] = io.NextInt()
		}
		const st = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
		s := io.NextLine()
		for i, cnt := 0, 0; i < len(s); i, cnt = i+1, (cnt+1)%n {
			idx := strings.IndexRune(st, rune(s[i]))
			c := st[(idx-k[cnt]+52)%52]
			io.Printf("%c", c)
		}
		io.Println()
	}
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := make([]interface{}, 0, len(a))
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := make([]interface{}, 0, len(a))
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #include <iostream>
#include <vector>
#include <string>
using namespace std;

const vector<char> ss = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
                         'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};

int main  ()
{
    int n;
    while (cin >> n, n) {
        vector<int> v(n);
        for (auto &i : v) cin >> i;
        string str;
        cin >> str;
        for (int i = 0; i < str.size(); i++) {
            int t = (str[i] - (('a' <= str[i] && str[i] <= 'z') ? 'a' : ('A' - 26)) - v[i % n] + 52) % 52;
            cout << ss[t];
        }
        cout << endl;
    }

    return 0;
}

C++: // #define _GLIBCXX_DEBUG // for STL debug (optional)
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
#include <bitset>
using namespace std;

#define debug(...) fprintf(stderr, __VA_ARGS__)
#define int long long int
 
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
 
typedef pair<int, int> pii;
typedef long long ll;
 
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
const ll INF = 1001001001001001LL;
const ll MOD = 1000000007LL;
 
signed main() {
    string pat = "";
    for(int i=0; i<26; i++) pat += (char)('a' + i);
    for(int i=0; i<26; i++) pat += (char)('A' + i);

    const int S = 52;
    int N;
    while(cin >> N, N) {
        vector<int> K(N);
        for(int i=0; i<N; i++) cin >> K[i];

        string ans = "";
        string s; cin >> s;
        int len = s.length();
        for(int i=0; i<len; i++) {
            int idx = pat.find(s[i]);
            int val = K[i % N];
            val %= S;
            idx = (idx - val + S) % S;
            ans += pat[idx];
        }
        cout << ans << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <iomanip>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <complex>
#include <cstring>
#include <cstdlib>
#include <string>
#include <cmath>
#include <cassert>
#include <queue>
#include <set>
#include <map>
#include <valarray>
#include <bitset>
#include <stack>
using namespace std;

#define REP(i,n) for(int i=0;i<(int)n;++i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define ALL(c) (c).begin(), (c).end()
#define chmax(a,b) (a<(b)?(a=b,1):0)
#define chmin(a,b) (a>(b)?(a=b,1):0)
#define valid(y,x,h,w) (0<=y&&y<h&&0<=x&&x<w)
const int INF = 1<<29;
const double EPS = 1e-8;
const double PI = acos(-1);
typedef pair<int,int> pii;
typedef long long ll;

int alpha2int(char c) {
  if (isupper(c)) return c-'A'+26;
  else return c-'a';
}
char int2alpha(int i) {
  if (i<26) return 'a'+i;
  else return 'A'+i-26;
}

int main() {
  int n;
  while(cin >> n, n) {
    int k[n];
    REP(i,n) cin >> k[i];
    string s; cin >> s;
    REP(i,s.size()) {
      s[i] = int2alpha((alpha2int(s[i])+52-k[i%n])%52);
    }
    cout << s << endl;

  }
}

C++: #define _USE_MATH_DEFINES
#define INF 0x3f3f3f3f

#include <iostream>
#include <cstdio>
#include <sstream>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <queue>
#include <stack>
#include <limits>
#include <map>
#include <string>
#include <cstring>
#include <set>
#include <deque>
#include <bitset>
#include <list>
#include <cctype>
#include <utility>
  
using namespace std;
  
typedef long long ll;
typedef pair <int,int> P;
typedef pair <int,P> PP;
  
static const double EPS = 1e-8;
  
static const int tx[] = {0,1,0,-1};
static const int ty[] = {-1,0,1,0};

static const string stations = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

int main(){

  int n;
  while(~scanf("%d",&n)){
    if(n==0) break;

    int back_dist[101];
    for(int i=0;i<n;i++){
      scanf("%d",back_dist+i);
    }
    string str;
    cin >> str;

    int back_idx = 0;
    for(int i=0;i<str.size();i++){
      int pos = lower_bound(stations.begin(),stations.end(),str[i]) - stations.begin();
      str[i] = stations[(pos - back_dist[back_idx] + stations.size()) % stations.size()];
      back_idx++;
      back_idx %= n;
    }

    cout << str << endl;
  }
}

C++: #include<bits/stdc++.h>
using namespace std;

char Conv(char c , int key){

  char ls[]="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
  int indx;

  if(c>='a')indx = c-'a';
  else indx = 26+c-'A';

  if(indx < key)indx += 52;
  
  return ls[(indx-key)%52];

}

int main(){

  string eki;
  int n;
  int key[100];
  int indx;

  while(cin >> n , n){

    for(int i=0; i<n; i++)cin>>key[i];

    indx = 0;
    cin >> eki;

    for(int i=0; i<(int)eki.size(); i++){
      eki[i] = Conv(eki[i],key[indx]);
      indx = (indx+1)%n;
    }

    cout << eki << endl;

  }

  return 0;
}