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 <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <numeric>

using namespace std;
using ll = long long;

string J(const string& S)
{
    const int N = S.size();
    string s;
    s.resize(N);
    for (int i = 0; i < N; i++) {
        s[i] = S[(i + 1) % N];
    }
    return s;
}

string C(const string& S)
{
    const int N = S.size();
    string s;
    s.resize(N);
    for (int i = 0; i < N; i++) {
        s[i] = S[(i + N - 1) % N];
    }
    return s;
}

string E(const string& S)
{
    const int N = S.size();
    const int shift = (N + 1) / 2;
    string s;
    s.resize(N);
    for (int i = 0; i < N; i++) {
        if (i + shift < N) {
            s[i] = S[i + shift];
        } else {
            s[i] = S[i - shift];
        }
    }
    return s;
}

string A(const string& S)
{
    string s = S;
    reverse(s.begin(), s.end());
    return s;
}

string P(const string& S)
{
    const int N = S.size();
    string s = S;
    for (int i = 0; i < N; i++) {
        if (s[i] >= '1' and s[i] <= '9') {
            s[i]--;
        } else if (s[i] == '0') {
            s[i] = '9';
        }
    }
    return s;
}

string M(const string& S)
{
    const int N = S.size();
    string s = S;
    for (int i = 0; i < N; i++) {
        if (s[i] >= '0' and s[i] <= '8') {
            s[i]++;
        } else if (s[i] == '9') {
            s[i] = '0';
        }
    }
    return s;
}

string op(const char c, const string& S)
{
    switch (c) {
    case 'J':
        return J(S);
    case 'C':
        return C(S);
    case 'E':
        return E(S);
    case 'A':
        return A(S);
    case 'P':
        return P(S);
    case 'M':
        return M(S);
    }
}

int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        string s;
        cin >> s;
        reverse(s.begin(), s.end());
        string m;
        cin >> m;
        for (const char c : s) {
            m = op(c, m);
        }
        cout << m << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;

int main(){
    int n;
    cin >> n;
    while( n-- ){
        string p, m;
        cin >> p >> m;
        reverse( p.begin(), p.end() );
        for( size_t i = 0; i < p.length(); i++ ){
            switch(p[i]){
                case 'J':{
                    char tmp = m[m.length() - 1];
                    for( size_t j = m.length() - 1; j > 0; j-- ){
                        //if( j == 0 ){
                        //}else{
                            m[j] = m[j-1];
                        //}
                        //cout << m[j] << endl;
                    }
                    m[0] = tmp;
                    break;
                }case 'C':{
                    char tmp = m[0];
                    for( size_t j = 0; j < m.length(); j++ ){
                        if( j == m.length() - 1 ) m[j] = tmp;
                        else m[j] = m[j+1];
                    }
                    break;
                }case 'E':{
                    string tmp = m.substr( 0, m.length() / 2 );
                    m = m.substr( (m.length() + 1) / 2 );
                    m.append( tmp );
                    break;
                }case 'A':{
                    reverse( m.begin(), m.end() );
                    break;
                }case 'P':{
                    for( size_t j = 0; j < m.length(); j++ ){
                        if( '1' <= m[j] && m[j] <= '9' ){
                            m[j]--;
                        }else if( '0' == m[j] ){
                            m[j] = '9';
                        }
                    }
                    break;
                }case 'M':{
                    for( size_t j = 0; j < m.length(); j++ ){
                        if( '0' <= m[j] && m[j] <= '8' ){
                            m[j]++;
                        }else if( '9' == m[j] ){
                            m[j] = '0';
                        }
                    }
                    break;
                }
            }
        }
        cout << m << endl;
    }
}