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<string>
#include<vector>
#include<cstdio>
using namespace std;
int main(){
  int n;
  string x;
  string st;
  cin >>n;
  for(int i=0;i<n;i++){
    cin >> x;
    cin >> st;
    for(int j=x.size()-1;j>=0;j--){
      if(x[j]=='C'){
	char stock;
	stock = st[0];
	st.erase(st.begin());
	st+=stock;
      }
      else if(x[j]=='J'){
	char stock;
	stock = st[st.size()-1];
	//	cout << "p1"<<endl;
	st.erase(st.size()-1);
	//cout <<"p2"<<endl;
	st.insert(st.begin(),stock);
      }
      else if(x[j]=='E'){
	string stock;
	int l=st.size()/2;
	for(int k=0;k<l;k++){
	  stock+=st[k];
	}
	string stock2;
	int od = st.size()%2;
	for(int k=l+od;k<l*2+od;k++){
	  stock2+=st[k];
	}
	char st3;
	if(od==1){st3+=st[l];
	  st=stock2+st3+stock;
	}
	else{
	  st=stock2+stock;
	}
      }
      else if(x[j]=='A'){
	string stock;
	for(int k=0;st.empty()!=true;k++){
	  stock += st[0];
	  st.erase(st.begin());
	}
	//cout << stock <<endl;
	for(int k=stock.size()-1;k>=0;k--){
	  st+=stock[k];
	}
      }
      else if(x[j]=='M'){
	for(int k=0;k<st.size();k++){
	  if(st[k]>='0'&&st[k]<'9'){
	    st[k]++;
	  }
	  else if(st[k]=='9'){
	    st[k]='0';
	  }
	}
      }
      else if(x[j]=='P'){
	for(int k=0;k<st.size();k++){
	  if(st[k]>'0'&&st[k]<='9'){
	    st[k]--;
	  }
	  else if(st[k]=='0'){
	    st[k]='9';
	  }
	}
      }	

      //cout <<"it is "<<x[j]<<endl;
      //cout << st << endl;
    }
    cout << st << endl;
  }
  return 0;
}

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


char rmsg[50];
int len;
void J();
void C();
void E();
void A();
void P();
void M();


int main(){
  int n;
  char msger[10];

  cin >> n;
  for (int i=0;i<n;i++){
    cin >> msger >> rmsg;
    // cin >> rmsg;
    len=strlen(rmsg);
    //cout << rmsg << endl;
    for (int j=strlen(msger)-1;j>=0;j--){
      switch (msger[j]){
      case 'J':J();break;
      case 'C':C();break;
      case 'E':E();break;
      case 'A':A();break;
      case 'P':P();break;
      case 'M':M();break;
      }
      //cout <<msger[j]<<" "<< rmsg << endl;
    }
    cout << rmsg << endl;
  }
}

void C(){
  char t=rmsg[0];

  for (int i=0;i<len-1;i++){
    rmsg[i]=rmsg[i+1];
  }
  rmsg[len-1]=t;
}
void J(){
  char t=rmsg[len-1];

  for (int i=len-1;i>0;i--){
    rmsg[i]=rmsg[i-1];
  }
  rmsg[0]=t;
}
void E(){
  char t;
  if (len<=1)return;
  for (int i=0;i<(len/2);i++){
    t=rmsg[i];
    rmsg[i]=rmsg[i+((len+1)/2)];
    rmsg[i+((len+1)/2)]=t;
  }
}
void A(){
  char t;
  for (int i=0;i<len-i;i++){
    t=rmsg[i];
    rmsg[i]=rmsg[len-i-1];
    rmsg[len-i-1]=t;
  }
}
void P(){
  for (int i=0;i<len;i++){
    if ('0'<rmsg[i]&&rmsg[i]<='9'){
      rmsg[i]--;
    }else if (rmsg[i]=='0'){
      rmsg[i]='9';
    }
  }
}
void M(){
  for (int i=0;i<len;i++){
    if ('0'<=rmsg[i]&&rmsg[i]<'9'){
      rmsg[i]++;
    }else if (rmsg[i]=='9'){
      rmsg[i]='0';
    }
  }
}

C++: #include <cstdio>
#include <cassert>
#include <iostream>
#include <sstream>
#include <algorithm>
#include <numeric>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <array>

using namespace std;

#define all(c) begin(c), end(c)
#define dump(c) cerr << "> " << #c << " = " << (c) << endl
#define REP(i, a, b) for (int i = (a); i < (int)(b); i++)
#define rep(i, n) REP(i, 0, n)

typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;

const int INF = 1001001001;
const double EPS = 1e-10;


template<typename T1,typename T2>
ostream& operator<<(ostream& os, const pair<T1,T2>& p){
  return os << '(' << p.first <<',' << p.second << ')';
}
template<typename T>
ostream& operator<<(ostream& os, const vector<T>& a){
  os << '[';
  rep(i,a.size()) os << (i ? " " : "") << a[i];
  return os << ']';
}

int main() {
  int N; cin >> N;
  while(N--) {
    string O, M; cin >> O >> M;
    reverse(all(O));
    for(char o : O) {
      if(o == 'J') {
        M = M.substr(M.size() - 1) + M.substr(0, M.size() - 1);
      }
      if(o == 'C') {
        M = M.substr(1) + M.substr(0, 1);
      }
      if(o == 'E') {
        int h = M.size() / 2;
        M = M.substr(M.size() - h) + M.substr(h, M.size() & 1) + M.substr(0, h);
      }
      if(o == 'A') {
        reverse(all(M));
      }
      if(o == 'P') {
        for(char &c : M) if(isdigit(c)) c = (c - '0' - 1 + 10) % 10 + '0';
      }
      if(o == 'M') {
        for(char &c : M) if(isdigit(c)) c = (c - '0' + 1) % 10 + '0';
      }
    }

    cout << M << endl;
  }
  
  
  return 0;
}