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;
#define INF 1000000000

string f_J(string s){
    
    char c = s[0];
    for(int i = 0; i < s.size() - 1; i++){
        s[i] = s[i + 1];
    }
    s[s.size() - 1] = c;
    return s;
}

string f_C(string s){

    char c = s[s.size() - 1];
    for(int i = s.size() - 1; i > 0; i--){
        s[i] = s[i - 1];
    }
    s[0] = c;
    return s;
}

string f_E(string s){

    int n = s.size();
    if(n % 2 == 0){

        string r = "", l = "";
        for(int i = 0; i < n/2; i++){
            l = l + s[i];
        }
        for(int i = n/2; i < n; i++){
            r = r + s[i];
        }

        s = r + l;        
    }else{

        string r = "", l = "";
        for(int i = 0; i < n/2; i++){
            r = r + s[i];
        }

        for(int i = n/2 + 1; i < n; i++){
            l = l + s[i];
        }

        s = l + s[n/2] + r;
    }

    return s;
}

string f_A(string s){
    
    reverse(s.begin(), s.end());
    return s;
}

string f_P(string s){

    for(int i = 0; i < s.size(); i++){
        if('0' <= s[i] && s[i] <= '8'){
            s[i]++;
        }else if(s[i] == '9'){
            s[i] = '0';
        }
    }

    return s;
}

string f_M(string s){

    for(int i = 0; i < s.size(); i++){
        if('1' <= s[i] && s[i] <= '9'){
            s[i]--;
        }else if(s[i] == '0'){
            s[i] = '9';
        }
    }

    return s;
}

int main(){

    int n; cin >> n;
    for(int i = 0; i < n; i++){
        string t; cin >> t;
        string s; cin >> s;
        for(int j = t.size() - 1; j >= 0; j--){

            if(t[j] == 'J') s = f_C(s);
            if(t[j] == 'C') s = f_J(s);
            if(t[j] == 'E') s = f_E(s);
            if(t[j] == 'A') s = f_A(s);
            if(t[j] == 'P') s = f_M(s);
            if(t[j] == 'M') s = f_P(s);
        }

        cout << s << endl;
    }

    return 0;
}

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>::reverse_iterator i=cmd.rbegin(); i!=cmd.rend(); i++)
        {
            text = op[*i](text);
        }
        cout << text << endl;
    }
}

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

int main(){
	int N;
	cin >> N;
	while(N--){
		string order, mess;
		cin >> order >> mess;
		for(int i = order.size() - 1; i >= 0; i--){
			char c;
			switch(order[i]){
				case 'J':
					c = mess[mess.size() - 1];
					for(int j = mess.size() - 1; j > 0; j--){
						mess[j] = mess[j - 1];
					}
					mess[0] = c;
					break;
				case 'C':
					c = mess[0];
					for(int j = 1; j < mess.size(); j++){
						mess[j - 1] = mess[j];
					}
					mess[mess.size() - 1] = c;
					break;
				case 'E':
					if(mess.size() % 2){
						mess = mess.substr(mess.size() / 2 + 1) + mess[mess.size() / 2] + mess.substr(0, mess.size() / 2);
					}else{
						mess = mess.substr(mess.size() / 2) + mess.substr(0, mess.size() / 2) ;
					}
					break;

				case 'A':
					reverse(mess.begin(), mess.end());
					break;
				case 'P':
					for(int i = 0; i < mess.size(); i++){
						c = mess[i];
						if('0' <= c && c <= '9'){
							mess[i] = (c - '0' + 9) % 10 + '0';
						}
					}
					break;
				case 'M':
					for(int i = 0; i < mess.size(); i++){
						c = mess[i];
						if('0' <= c && c <= '9'){
							mess[i] = (c - '0' + 1) % 10 + '0';
						}
					}
					break;
			}
		}
		cout << mess << endl;
	}

}