Go: package main

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

func main() {
	io := NewIo()
	defer io.Flush()
	n := io.NextInt()
	for i := 0; i < n; i++ {
		s, t := io.NextLine(), io.NextLine()
		io.Println(f(s, t))
	}
}

func f(s, t string) string {
	for i := len(s) - 1; i >= 0; i-- {
		switch s[i] {
		case 'C':
			t = strings.Join([]string{t[1:], string(t[0])}, "")
		case 'J':
			t = strings.Join([]string{string(t[len(t)-1]), t[:len(t)-1]}, "")
		case 'E':
			if len(t)%2 == 1 {
				t = strings.Join([]string{t[len(t)/2+1:], string(t[len(t)/2]), t[:len(t)/2]}, "")
			} else {
				t = strings.Join([]string{t[len(t)/2:], t[:len(t)/2]}, "")
			}
		case 'A':
			r := []rune(t)
			for i, n := 0, len(r); i < n/2; i++ {
				r[i], r[n-i-1] = r[n-i-1], r[i]
			}
			t = string(r)
		case 'M':
			r := []rune(t)
			for i := 0; i < len(r); i++ {
				if '0' <= r[i] && r[i] < '9' {
					r[i]++
				} else if r[i] == '9' {
					r[i] = '0'
				}
			}
			t = string(r)
		case 'P':
			r := []rune(t)
			for i := 0; i < len(r); i++ {
				if '0' < r[i] && r[i] <= '9' {
					r[i]--
				} else if r[i] == '0' {
					r[i] = '9'
				}
			}
			t = string(r)
		}
	}
	return t
}

// 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<string>
#include<algorithm>
#include<iostream>
using namespace std;

string J(string s, int len) {
  return s.substr(1) + s[0];
}

string C(string s, int len) {
  return s[len-1] + s.substr(0,len-1);
}

string E(string s, int len) {
  if (len % 2 == 1) {
    return s.substr(len/2+1) + s[len/2] + s.substr(0, len/2);
  } else {
    return s.substr(len/2) + s.substr(0, len/2);
  }
}

string A(string s, int len) {
  reverse(s.begin(), s.end());
  return s;
}

string P(string s, int len) {
  for (int i = 0; i < len; i++) {
    if (!isdigit(s[i])) continue;
    if (s[i] == '9') s[i] = '0';
    else s[i]++;
  }
  return s;
}

string M(string s, int len) {
  for (int i = 0; i < len; i++) {
    if (!isdigit(s[i])) continue;
    if (s[i] == '0') s[i] = '9';
    else s[i]--;
  }
  return s;
}

int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    string messengers, crypt;
    cin >> messengers >> crypt;
    int len = crypt.length();
    reverse(messengers.begin(), messengers.end());
    for (char m : messengers) {
      if (m == 'J') {
        crypt = C(crypt, len);
      } else if (m == 'C') {
        crypt = J(crypt, len);
      } else if (m == 'E') {
        crypt = E(crypt, len);
      } else if (m == 'A') {
        crypt = A(crypt, len);
      } else if (m == 'P') {
        crypt = M(crypt, len);
      } else if (m == 'M') {
        crypt = P(crypt, len);
      }
    }
    cout << crypt << endl;
  }
}

C++: #include <bits/stdc++.h>
using namespace std;
#define FOR(i,k,n) for(int i = (k); i < (n); i++)
#define REP(i,n) FOR(i,0,n)
#define INF 114514810
#define MOD 1000000007
#define ALL(a) (a).begin(),(a).end()
#define pb(x) push_back(x)
#define ms(m,v) memset(m,v,sizeof(m))
#define D10  fixed<<setprecision(10) 
typedef vector<int> vi;
typedef vector<string> vs;
typedef pair<int, int> P;
typedef long long ll;
struct edge{ int from, to, cost; };

string s, mes;
string solve(string s, char c)
{
	if (c == 'C') return s.substr(1) + s[0];
	if (c == 'J') return s[s.size() - 1] + s.substr(0, s.size() - 1);
	if (c == 'E')
	{
		if (s.size() % 2 == 0) return s.substr(s.size() / 2, s.size() - 1) + s.substr(0, s.size()/2);
		else return s.substr(s.size() / 2 + 1, s.size()) + s[s.size() / 2] + s.substr(0, s.size() / 2);
	}
	if (c == 'A')
	{
		string r = "";
		REP(i, s.size()) r += s[s.size() - i - 1];
		return r;
	}
	if (c == 'M')
	{
		string r = "";
		REP(i, s.size())
		{
			if (isdigit(s[i]))
			{
				if (s[i] == '9') r += '0';
				else r += s[i] + 1;
			}
			else r += s[i];
		}
		return r;
	}
	if (c == 'P')
	{
		string r = "";
		REP(i, s.size())
		{
			if (isdigit(s[i]))
			{
				if (s[i] == '0') r += '9';
				else r += s[i] - 1;
			}
			else
			{
				r += s[i];
			}
		}
		return r;
	}
}
int main()
{
	int n;
	cin >> n;

	REP(i, n)
	{
		cin >> mes >> s;
		for (int i = mes.size() - 1; i >= 0;i--)
		{
			s = solve(s, mes[i]);
		}
		cout << s << endl;
	}
}

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

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n; cin >> n;
    for (;n--;){
        string order,S; cin >> order >> S;
        int s=S.size();
        reverse(order.begin(),order.end());
        for (int i=0;i<order.size();++i){
            if (order[i]=='J'){
                S+=S;
                S=S.substr(s-1,s);
            }
            if (order[i]=='C'){
                S+=S;
                S=S.substr(1,s);
            }
            if (order[i]=='E'){
                for (int j=0;j<s/2;++j) swap(S[j],S[j+(s+1)/2]);
            }
            if (order[i]=='A'){
                reverse(S.begin(),S.end());
            }
            if (order[i]=='P'){
                for (int j=0;j<s;++j){
                    int x=S[j]-'0';
                    if (x<10) S[j]='0'+(x+9)%10;
                }
            }
            if (order[i]=='M'){
                for (int j=0;j<s;++j){
                    int x=S[j]-'0';
                    if (x<10) S[j]='0'+(x+1)%10;
                }
            }
        }
        cout << S << '\n';
    }
}