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>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) for(int i = 0; i < (b); i++)
#define all(a) (a).begin(), (a).end()
#define debug(x) cout << "debug " << x << endl;
const int INF = 100000000;
using namespace std;

int main(){
    int n;
    cin >> n;
    rep(i,n){
        list<char> li;
        list<char>::iterator it;
        string order, s, temp;
        cin >> temp >> s;
        rep(j,s.size()) li.emplace_back(s[j]);
        for(int j = temp.size() - 1; j >= 0; j--) order += temp[j];
        rep(j,order.size()){
            if(order[j] == 'C'){
                li.emplace_back(*li.begin());
                li.pop_front();
            }else if(order[j] == 'J'){
                li.emplace_front(*(--li.end()));
                li.pop_back();
            }else if(order[j] == 'E'){
                int m = li.size();
                rep(k, m / 2){
                    li.emplace_back(*li.begin());
                    li.pop_front();
                }
                if(m % 2){
                    it = li.begin();
                    rep(k, m / 2 + 1) *it++;
                    li.insert(it, *li.begin());
                    li.pop_front();
                }
            }else if(order[j] == 'A'){
                li.reverse();
            }else if(order[j] == 'M'){
                for(it = li.begin(); it != li.end(); it++){
                    if(*it >= '0' && *it <= '8') *it = *it + 1;
                    else if(*it == '9') *it = '0';
                }
            }else if(order[j] == 'P'){
                for(it = li.begin(); it != li.end(); it++){
                    if(*it >= '1' && *it <= '9') *it = *it - 1;
                    else if(*it == '0') *it = '9';
                }
            }
        }
        for(auto t: li){
            cout << t;
        }
        cout << endl;
    }
}

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

int main() {
    int n; cin>>n;
    for(int i=0; i<n; i++){
        string order, message;
        cin>>order>>message;
        reverse(order.begin(), order.end());
        for(char c : order){
            if(c == 'J'){
                rotate(message.rbegin(), message.rbegin()+1, message.rend());
            }else if(c == 'C'){
                rotate(message.begin(), message.begin()+1, message.end());
            }else if(c == 'E'){
                if(message.size()%2 == 0){
                    message = message.substr(ceil(message.size()/2.0), message.size()) + message.substr(0, message.size()/2);
                }else{
                    int index = message.size()/2;
                    message = message.substr(ceil(message.size()/2.0), message[index]) + message[index] + message.substr(0, message.size()/2);
                }
            }else if(c == 'A'){
                reverse(message.begin(), message.end());
            }else if(c == 'P'){
                for(int j=0; j<message.size(); j++){
                    if(isdigit(message[j])){
                        int digit = stoi(message.substr(j,1).c_str());
                        message[j] = to_string(digit == 0 ? 9 : digit-1)[0];
                    }
                }
            }else{
                for(int j=0; j<message.size(); j++){
                    if(isdigit(message[j])){
                        int digit = stoi(message.substr(j,1).c_str());
                        message[j] = to_string((digit+1)%10)[0];
                    }
                }
            }
        }
        cout << message << endl;
    }
}