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;

string J(const string& s)
{
    int lasti = s.size() - 1;
    return s[lasti] + s.substr(0, lasti);
}

string C(const string& s)
{
    return s.substr(1) + s[0];
}

string E(const string& s)
{
    int size = s.size();
    int hsize = size / 2;
    if(size&1) return s.substr(hsize+1) + s[hsize] + s.substr(0, hsize);
    else return s.substr(hsize) + s.substr(0, hsize);
}

string A(const string& s)
{
    return string(s.rbegin(), s.rend());
}

string P(const string& s)
{
    string r;
    for(basic_string<char>::const_iterator i=s.begin(); i!=s.end(); i++)
    {
        r.push_back(('0'<=*i && *i<='9') ? (*i - '0' + 9) % 10 + '0' : *i);
    }
    return r;
}

string M(const string& s)
{
    string r;
    for(basic_string<char>::const_iterator i=s.begin(); i!=s.end(); i++)
    {
        r.push_back(('0'<=*i && *i<='9') ? (*i - '0' + 1) % 10 + '0' : *i);
    }
    return r;
}



int main()
{
    string (*op[128])(const string&);
    op['J'] = J;
    op['C'] = C;
    op['E'] = E;
    op['A'] = A;
    op['P'] = P;
    op['M'] = M;

    int n;
    cin >> n;
    while(n--)
    {
        string cmd, text;
        cin >> cmd >> text;
        for(basic_string<char>::iterator i=cmd.begin(); i!=cmd.end(); i++)
        {
            text = op[*i](text);
        }
        cout << text << endl;
    }
}

C++: #include <iostream>
#include <iomanip>
#include <algorithm>
#include <string>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>

using std::cin;
using std::cout;
using std::endl;
using std::setprecision;
using std::fixed;
using std::pair;
using std::make_pair;
using std::string;
using std::vector;
using std::list;
using std::map;
using std::set; // insert erase find count
using std::queue;
using std::priority_queue;
using std::stack;
/* c++11
#include <tuple>
using std::tuple; 
using std::make_tuple;
using std::get; // tuple std::get<NUM>(t); (0 <= NUM <= 2)
 */

typedef vector<int> VI;
typedef vector<vector<int> > VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<int, pair<int, int> > PIII;

void j(string &s) {
    int length = s.length();
    s = s.substr(length - 1, 1) + s.substr(0, length - 1);
    return;
}

void c(string &s) {
    int length = s.length();
    s = s.substr(1, length - 1) + s.substr(0, 1);
    return;
}

void e(string &s) {
    int length = s.length();
    if (length % 2 == 0) {
        s = s.substr(length / 2, length / 2) + s.substr(0, length / 2);
    } else {
        s = s.substr(length / 2 + 1, length / 2) + s.substr(length / 2, 1) + s.substr(0, length / 2);
    }
    return;
}
void a(string &s) {
    reverse(s.begin(), s.end());
    return;
}

void p(string &s) {
    int length = s.length();
    for (int i = 0; i < length; i++) {
        if (s[i] > '0' && s[i] <= '9') {
            s[i]--;
        } else if (s[i] == '0') {
            s[i] = '9'; 
        }
    }
    return;
}

void m(string &s) {
    int length = s.length();
    for (int i = 0; i < length; i++) {
        if (s[i] >= '0' && s[i] < '9') {
            s[i]++;
        } else if (s[i] == '9') {
            s[i] = '0'; 
        }
    }
    return;
}

int main(void) {
    int n;
    cin >> n;
    string order;
    string mess;
    for (int loop = 0; loop < n; loop++) {
        cin >> order >> mess;
        int order_length = order.length();
        for (int i = order_length - 1; i >= 0; i--) {
            if (order[i] == 'J') {
                j(mess);
            } else if (order[i] == 'C') {
                c(mess);
            } else if (order[i] == 'E') {
                e(mess);
            } else if (order[i] == 'A') {
                a(mess);
            } else if (order[i] == 'P') {
                p(mess);
            } else if (order[i] == 'M') {
                m(mess);
            }
        }
        cout << mess << endl;
    }
    return 0;
}