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 <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MOD = 1e9 + 7;

int main()
{
  int n;
  cin >> n;
  vector<string> ans;
  while (n--)
  {
    string messengers, message;
    cin >> messengers >> message;
    reverse(messengers.begin(), messengers.end());
    int len = message.size();
    for (int i = 0; i < messengers.size(); ++i)
    {
      if (messengers[i] == 'J')
      {
        rotate(message.rbegin(), message.rbegin() + 1, message.rend());
      }
      else if (messengers[i] == 'C')
      {
        rotate(message.begin(), message.begin() + 1, message.end());
      }
      else if (messengers[i] == 'E')
      {
        string tmp = "";
        tmp += message.substr(len % 2 == 0 ? len / 2 : len / 2 + 1, len / 2);
        if (len % 2 == 1)
          tmp += message[len / 2];
        tmp += message.substr(0, len / 2);
        message = tmp;
      }
      else if (messengers[i] == 'A')
      {
        reverse(message.begin(), message.end());
      }
      else if (messengers[i] == 'P')
      {
        for (int j = 0; j < len; ++j)
        {
          if ('0' <= message[j] && message[j] <= '9')
            message[j] = char((10 + message[j] - 1 - '0') % 10 + '0');
        }
      }
      else if (messengers[i] == 'M')
      {
        for (int j = 0; j < len; ++j)
        {
          if ('0' <= message[j] && message[j] <= '9')
            message[j] = char((message[j] + 1 - '0') % 10 + '0');
        }
      }
    }
    ans.push_back(message);
  }
  for (auto &e : ans)
    cout << e << endl;

  return 0;
}

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

typedef unsigned long long ull;
#define loop(i,a,b) for(int i=(a);i<ull(b);++i)
#define rep(i,n) loop(i,0,n)

const double eps = 1e-10;
const double pi  = acos(-1.0);
const double inf = (int)1e8;

int main(){
    int q;
    cin >> q;
    rep(p, q){
        string s, m;
        cin >> s >> m;
        reverse(s.begin(), s.end());
        for(int i=0; i< s.size(); i++){
            if(s[i] == 'J'){
                if(1 <= m.size())m = m.substr(m.size()-1, 1) + m.substr(0, m.size()-1);
            }
            if(s[i] == 'C'){
                if(1 <= m.size())m = m.substr(1) + m.substr(0, 1);
            }
            if(s[i] == 'E'){
                if(1 <= m.size()){
                    if(m.size()%2 == 0)m = m.substr(m.size()/2)+ m.substr(0, m.size()/2);
                    else m = m.substr(m.size()/2+1) + m.substr(m.size()/2, 1) + m.substr(0, m.size()/2);
                }
            }
            if(s[i] == 'A') reverse(m.begin(), m.end());
            if(s[i] == 'P'){
                for(int j=0; j< m.size(); j++){
                    if('0' <= m[j] && m[j] <= '9'){
                        if(m[j] == '0') m[j] = '9';
                        else m[j]--;
                    }
                }
            }
            if(s[i] == 'M'){
                for(int j=0; j< m.size(); j++){
                    if('0' <= m[j] && m[j] <= '9'){
                        if(m[j] == '9') m[j] = '0';
                        else m[j]++;
                    }
                }
            }
        }
        cout << m << endl;
    }
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <algorithm>
#include <sstream>

#define REP(i,k,n) for(int i=k;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)

using namespace std;
typedef long long ll;

int main() {
    int n;
    cin >> n;

    rep(i,n) {
        string a,b;
        cin >> a >> b;

        rep(j,a.size()) {
            if(a[j] == 'J') {
                rotate(b.rbegin(),b.rbegin()+1,b.rend());
            }
            if(a[j] == 'C') {
                rotate(b.begin(),b.begin()+1,b.end());
            }
            if(a[j] == 'E') {
                stringstream ss;
                REP(k,b.size()/2,b.size()) {
                    ss << b[k];
                }

                rep(k,b.size()/2) {
                    ss << b[k];
                }

                b = ss.str();
            }
            if(a[j] == 'A') {
                reverse(b.begin(),b.end());
            }
            if(a[j] == 'P') {
                rep(k,b.size()) {
                    if(b[k] == '0') b[k] = '9';
                    else if('1' <= b[k] && b[k] <= '9') b[k]--;
                }
            }
            if(a[j] == 'M') {
                rep(k,b.size()) {
                    if(b[k] == '9') b[k] = '0';
                    else if('0' <= b[k] && b[k] <= '8') b[k]++;
                }
            }
        }

        cout << b << endl;

    }

    return 0;
}