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>

using namespace std;

int main(void){
  int n;cin>>n;
  for(int i=0;i<n;++i){
    string proc,mes;
    cin>>proc>>mes;
    for(int j=proc.size()-1;j>=0;--j){
      if(proc[j]=='J'){
        mes = mes[mes.size()-1] + mes.substr(0,mes.size()-1);
      }else if(proc[j]=='C'){
        mes = mes.substr(1,mes.size()-1) + mes[0];
      }else if(proc[j]=='E'){
      	int len = mes.size();
      	string centre;
      	if(len%2) centre = mes[len/2];
      	string lft = mes.substr(0, len/2);
      	string rgt = mes.substr(len-len/2, len/2);
        mes = rgt + centre + lft;
      }else if(proc[j]=='A'){
      	string tmp;
      	for(int k=mes.length()-1;k>=0;--k)tmp+=mes[k];
        mes = tmp;
      }else if(proc[j]=='P'){
        for(int k=0;k<mes.length();++k){
          if('0'<=mes[k] && mes[k]<='9') mes[k]=(9+mes[k]-'0')%10+'0';
        }
      }else if(proc[j]=='M'){
        for(int k=0;k<mes.length();++k){
          if('0'<=mes[k] && mes[k]<='9') mes[k]=(1+mes[k]-'0')%10+'0';
        }
      }
    }
    cout<<mes<<endl;
  }
  return 0;
}

C++: #include <cstdio>
#include <algorithm>
using std::swap;

void J(char s[], int len){
    char tmp = s[len-1];
    for(int i=len-1;i>0;i--){
        s[i] = s[i-1];
    }s[0] = tmp;
}
void C(char s[], int len){
    char tmp = s[0];
    for(int i=0;i<len-1;i++){
        s[i] = s[i+1];
    }s[len-1] = tmp;
}
void E(char s[], int len){
    int mid = len/2;
    for(int i=0;i<mid;i++){
        swap(s[i], s[len-mid+i]);
    }
}
void A(char s[], int len){
    char tmp = s[len-1];
    for(int i=0;i<len-1-i;i++){
        swap(s[i], s[len-1-i]);
    }
}
void P(char s[], int len){
    for(int i=0;i<len-1;i++){
        if('0'<=s[i] && s[i]<='9'){
            s[i] = '0'+(s[i]-'0'+9)%10;
        }
    }
}
void M(char s[], int len){
    for(int i=0;i<len-1;i++){
        if('0'<=s[i] && s[i]<='9'){
            s[i] = '0'+(s[i]-'0'+1)%10;
        }
    }
}

int main(){
    int N;
    scanf("%d", &N);
    while(N--){
        char s1[50], s2[50];
        scanf("%s %s", s1, s2);
        int len1;
        for(len1=0 ; s1[len1]!='\0' ; len1++);
        int len2;
        for(len2=0 ; s2[len2]!='\0' ; len2++);
        
        for(int i=len1-1;i>=0;i--){
            if(s1[i] == 'J') J(s2, len2);
            if(s1[i] == 'C') C(s2, len2);
            if(s1[i] == 'E') E(s2, len2);
            if(s1[i] == 'A') A(s2, len2);
            if(s1[i] == 'P') P(s2, len2);
            if(s1[i] == 'M') M(s2, len2);
        }
        printf("%s\n", s2);
    }
    return 0;
}