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 <functional>
#include <cstdlib>
#include <sstream>
#include <string>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <complex>
#include <vector>
#include <bitset>
#include <cstdio>
#include <cmath>
#include <time.h>
#include <tuple>
#define all(c) ((c).begin(),(c).end())
#define rall(c) ((c).rbegin(),(c).rend())
//#define sort(v,n) sort(v,v+n)
#define ll long long
#define fi first
#define se second
#define inf 999999999
using namespace std;
const ll MOD = 1e9 + 7;
const double PI = acos(-1.0);
//---------------------------------------------------------------------------------------------//
int n;
inline string j(string a) {
	string res;
	res = a.substr(1, a.length() - 1);
	res += a[0];
	return res;
}
inline string c(string a) {
	string res;
	res = a[a.length() - 1];
	res += a.substr(0, a.length() - 1);
	return res;
}
inline string e(string a) {
	string res, b, c;
	if ((int)a.length() & 1) {
		b = a.substr(0, a.length() / 2);
		c = a.substr(a.length() / 2 + 1, a.length() / 2);
		//cout << "b=" << b << " c=" << c << endl;
		res = c;
		res += a[a.length() / 2];
		res += b;
		return res;
	}
	else {
		b = a.substr(0, a.length() / 2);
		c = a.substr(a.length() / 2, a.length() / 2);
		res = c + b;
		return res;
	}
}
inline string a(string a) {
	reverse(a.begin(), a.end());
	return a;
}
inline string p(string a) {
	char b[] = { '1','2','3','4','5','6','7','8','9','0' };
	for (int i = 0; i < a.length(); i++) {
		for (int j = 0; j < 10; j++) {
			if (a[i] == b[j]) {
				if (j < 9) {
					a[i] = b[j + 1];
				}
				else {
					a[i] = b[0];
				}
				j = 10;
			}
		}
	}
	return a;
}
inline string m(string a) {
	char b[] = { '1','2','3','4','5','6','7','8','9','0' };
	for (int i = 0; i < a.length(); i++) {
		for (int j = 0; j < 10; j++) {
			if (a[i] == b[j]) {
				if (j > 0) {
					a[i] = b[j - 1];
				}
				else {
					a[i] = b[9];
				}
				j = 10;
			}
		}
	}
	return a;
}
int main() {
	cin >> n;
		for (int i = 0; i < n; i++) {
			string s, t;
			cin >> s >> t;
			for (int k = s.length() - 1; k >= 0; k--) {
				if (s[k] == 'A') {
					t=a(t);
				}
				else if (s[k] == 'J') {
					t=c(t);
				}
				else if (s[k] == 'M') {
					t=p(t);
				}
				else if (s[k] == 'P') {
					t=m(t);
				}
				else if (s[k] == 'E') {
					t=e(t);
				}
				else {
					t=j(t);
				}
				//cout <<"t="<< t << endl;
			}
			cout << t << endl;
		}
	return 0;
}

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

using namespace std;

int main () {
  int n;

  cin >> n;
  for( int i = 0; i < n; i++ ) {
    string commands, mes;
    cin >> commands >> mes;
    int len = commands.length();
    int meslen = mes.length();
    for( int j = len - 1; j >= 0; j-- ) {
      switch( commands[ j ] ) {
        case 'C':
          mes = mes.substr( 1 ) + mes[ 0 ];
          break;
        case 'J':
          mes = mes[ meslen - 1 ] + mes.substr( 0, meslen - 1 );
          break;
        case 'E':
          if( meslen % 2 == 1 ) {
            mes = 
              mes.substr( meslen / 2 + 1 ) + 
              mes[ meslen / 2 ] +
              mes.substr( 0, meslen / 2 );
          }else{
            mes = 
              mes.substr( meslen / 2 ) +
              mes.substr( 0, meslen / 2 ); 
          }
          break;
        case 'A':
          reverse( mes.begin(), mes.end() );
          break;
        case 'M':
          for( int k = 0; k < meslen; k++ ) {
            if( '0' <= mes[ k ] && mes[ k ] <= '8' ){
              mes[ k ]++;
            }else if( mes[ k ] == '9' ){
              mes[ k ] = '0';
            }
          }
          break;
        case 'P':
          for( int k = 0; k < meslen; k++ ) {
            if( '1' <= mes[ k ] && mes[ k ] <= '9' ){
              mes[ k ]--;
            }else if( mes[ k ] == '0' ){
              mes[ k ] = '9';
            }
          }
          break;
      }
    }
    cout << mes << endl;
  }

  return EXIT_SUCCESS;
}