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 <iostream>
#include <algorithm>
#include <cctype>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
int main(){
	int n;
	cin >> n;
	rep(tt,n){
		string m,s;
		cin >> m >> s;
		rep(ii,m.size()){
			int i=m.size()-1-ii;
			if(m[i]=='A'){
				reverse(s.begin(),s.end());
			}
			if(m[i]=='C'){
				s+=s[0];
				s=s.substr(1,s.size()-1);
			}
			if(m[i]=='J'){
				s=s[s.size()-1]+s;
				s=s.substr(0,s.size()-1);
			}
			if(m[i]=='E'){
				string l,r;
				if(s.size()%2==0){
					l=s.substr(0,s.size()/2),r=s.substr(s.size()/2,s.size()/2);
					s=r+l;
				}else{
					l=s.substr(0,s.size()/2),r=s.substr(s.size()/2+1,s.size()/2);
					s=r+s[s.size()/2]+l;
				}
			}
			if(m[i]=='P'){
				rep(j,s.size()){
					if(isdigit(s[j])){
						if(s[j]=='0') s[j]='9';
						else s[j]--;
					}
				}
			}
			if(m[i]=='M'){
				rep(j,s.size()){
					if(isdigit(s[j])){
						if(s[j]=='9') s[j]='0';
						else s[j]++;
					}
				}
			}
		}
		cout << s << endl;
	}
}

C++: #include <iostream>
#include <string>

using namespace std;

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

    auto decryptJ = [](const string &s) {
        return s.back() + s.substr(0, s.size() - 1);
    };

    auto decryptC = [](const string &s) { return s.substr(1) + s.front(); };

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

    auto decryptA = [](const string &s) {
        auto r = s;
        reverse(begin(r), end(r));
        return r;
    };

    auto decryptP = [](const string &s) {
        auto r = s;
        for (auto &&c : r) {
            if (c < '0' || '9' < c) {
                continue;
            }

            c = (c - '0' + 10 - 1) % 10 + '0';
        }
        return r;
    };

    auto decryptM = [](const string &s) {
        auto r = s;
        for (auto &&c : r) {
            if (c < '0' || '9' < c) {
                continue;
            }

            c = (c - '0' + 1) % 10 + '0';
        }
        return r;
    };

    for (int i = 0; i < n; ++i) {
        string order, message;
        cin >> order;
        cin >> message;
        reverse(begin(order), end(order));

        for (auto &&c : order) {
            switch (c) {
            case 'J':
                message = decryptJ(message);
                break;
            case 'C':
                message = decryptC(message);
                break;
            case 'E':
                message = decryptE(message);
                break;
            case 'A':
                message = decryptA(message);
                break;
            case 'P':
                message = decryptP(message);
                break;
            case 'M':
                message = decryptM(message);
                break;
            }
        }
        cout << message << endl;
    }
}