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<string>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
int cs,s;string ord,st;
void op(char o){
	if(o=='A')reverse(st.begin(),st.end());
	if(o=='J')rotate(st.rbegin(),st.rbegin()+1,st.rend());
	if(o=='C')rotate(st.begin(),st.begin()+1,st.end());
	if(o=='E')swap_ranges(st.begin(),st.begin()+s/2,st.begin()+(s+1)/2);
	if(o=='P'||o=='M')rep(i,s)if('0'<=st[i]&&st[i]<='9')
	st[i]=(st[i]-'0'+(o=='P'?-1:1))%10+'0';
}
int main(){
	cin>>cs;
	while(cs--){
		cin>>ord>>st;s=st.size();
		rep(i,ord.size())op(ord[ord.size()-1-i]);
		cout<<st<<endl;
	}
	return 0;
}

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

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;
}

C++: #include <bits/stdc++.h>

using namespace std;

int day[101];
int n, q;
string moji;

void fJ()
{
	string s {moji[moji.length()-1]};
	for (int i = 0; i < moji.length()-1; i++) {
		s += moji[i];
	}
	moji = s;
}

void fC()
{
	string s = "";
	for (int i = 1; i < moji.length(); i++) {
		s += moji[i];
	}
	s += moji[0];
	moji = s;
}

void fE()
{
	int l = moji.length();
	string a="", b="", c="";
	if (l % 2) b += moji[l/2];
	for (int i = 0; i < l/2; i++) {
		a += moji[i];
	}
	for (int i = l/2 + l % 2; i < l; i++) {
		c += moji[i];
	}
	moji = c + b + a;
}

int fP()
{
	int l = moji.length();
	for (int i = 0; i < l; i++) {
		if (isdigit(moji[i])) {
			int t = moji[i] - '0';
			moji[i] = ((t+9) % 10) + '0';
		}
	}
}

int fM()
{
	int l = moji.length();
	for (int i = 0; i < l; i++) {
		if (isdigit(moji[i])) {
			int t = moji[i] - '0';
			moji[i] = ((t+1) % 10) + '0';
		}
	}
}

int fA()
{
	string s = "";
	int l = moji.length();
	for (int i = 0; i < l; i++) {
		s = moji[i] + s;
	}
	moji = s;
}


int main()
{
	int N;
	string hito;
	cin >> N;
	for (int i = 0; i < N; i++) {		
		cin >> hito >> moji;
		for (int j = hito.length()-1; j >= 0; j--) {
			if (hito[j] == 'J') fJ();
			if (hito[j] == 'C') fC();
			if (hito[j] == 'E') fE();
			if (hito[j] == 'A') fA();
			if (hito[j] == 'P') fP();
			if (hito[j] == 'M') fM();
		}
		cout << moji << endl;
	}
}

C++: #include<iostream>
#include<string>
using namespace std;
int main(){
	int n;
	string a,b;
	char c[100],d[100];
	cin>>n;
	for(int u=0;u<n;u++){
		cin>>a>>b;
		for(int i=0;i<b.size();i++){
			d[i]=b[i];
			c[i]=d[i];
		}
		for(int i=a.size()-1;i>=0;i--){
			if(a[i]=='J'){
				for(int i=0;i<b.size()-1;i++)
					c[i+1]=d[i];
				c[0]=d[b.size()-1];
			}
			if(a[i]=='C'){
				for(int i=0;i<b.size()-1;i++)
					c[i]=d[i+1];
				c[b.size()-1]=d[0];
			}
			if(a[i]=='E'){
				for(int i=0;i<b.size();i++){
					if(i<b.size()/2)
						c[i+b.size()-b.size()/2]=d[i];
					else
						c[i-b.size()+b.size()/2]=d[i];
				}
			}
			if(a[i]=='A'){
				for(int i=0;i<b.size();i++)
					c[i]=d[b.size()-1-i];
			}
			if(a[i]=='P'){
				for(int i=0;i<b.size();i++){
					bool check=false;
					if(c[i]>='1'&&c[i]<='9'){
						c[i]=c[i]-1;
						check=true;
					}
					else if(c[i]=='0'){
						c[i]='9';
						check=true;
					}
					if(check==false)
						c[i]=d[i];
				}
			}
			if(a[i]=='M'){
				for(int i=0;i<b.size();i++){
					bool check=false;
					if(c[i]>='0'&&c[i]<='8'){
						c[i]=c[i]+1;
						check=true;
					}
					else if(c[i]=='9'){
						c[i]='0';
						check=true;
					}
					if(check==false)
						c[i]=d[i];
				}
			}
			for(int i=0;i<b.size();i++)
				d[i]=c[i];
		}
		for(int i=0;i<b.size();i++)
			cout<<d[i];
		cout<<endl;
	}
	return 0;
}