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 <bits/stdc++.h>
using namespace std;
/*{{{*/  //template
#define rep(i,n) for(int i=0;i<n;i++)
constexpr int INF = numeric_limits<int>::max()/2;
constexpr long long LINF = numeric_limits<long long>::max()/3;
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
#define sz(x) (int)(x).size()
#define debug(x) cerr<<#x<<":"<<x<<endl
#define debug2(x,y) cerr<<#x<<","<<#y":"<<x<<","<<y<<endl
//struct fin{ fin(){ cin.tie(0); ios::sync_with_stdio(false); } } fin_;
struct Double{ double d; explicit Double(double x) : d(x){} };
ostream& operator<<(ostream& os,const Double x){ os << fixed << setprecision(20) << x.d; return os; }
template<typename T> ostream& operator<<(ostream& os,const vector<T>& vec){ os << "["; for(const auto& v : vec){ os << v << ","; } os << "]"; return os; }
template<typename T,typename U> ostream& operator<<(ostream& os,const pair<T,U>& p){ os << "(" << p.first << ","<< p.second <<")"; return os; }
template<typename T> ostream& operator<<(ostream& os,const set<T>& st){ os<<"{"; for(T v:st) os<<v<<","; os <<"}"; return os; }
template<typename T,typename U> inline void chmax(T &x,U y){ if(y>x) x = y; }
template<typename T,typename U> inline void chmin(T &x,U y){ if(y<x) x = y; }
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
ll gcd(ll a,ll b){ if(b==0) return a; else return gcd(b,a%b); }
//constexpr double eps = 1e-14; 
constexpr double eps = 1e-10; 
constexpr ll mod = 1e9+7;
const int dx[]={1,0,-1,0} ,dy[] = {0,1,0,-1};
/*}}}*/

string J(string t){
    string ret;
    ret.push_back(t[t.size()-1]);
    for(int i=0;i<sz(t)-1;i++){
        ret.pb(t[i]);
    }
    return ret;
}

string C(string t){
    string ret;
    for(int i=1;i<sz(t);i++){
        ret.pb(t[i]);
    }
    ret.pb(t[0]);
    return ret;
}

string E(string s){
    if(s.size()%2==0){
        int t = s.size();
        string s1 = s.substr(0,t/2);
        string s2 = s.substr(t/2,t/2);

        return s2+s1;
    }else{
        int t = s.size();
        string s1 = s.substr(0,t/2);
        string s2 = s.substr(t/2+1,t/2);
        char c = s[t/2];
        string ret = s2;
        ret.pb(c);
        ret += s1;
        return ret;
    }
}

string A(string s){
    string ret = s;
    reverse(all(ret));
    return ret;
}

string P(string s){
    for(int i=0;i<sz(s);i++){
        if('1'<=s[i] and s[i]<='9') s[i]--;
        else if(s[i]=='0') s[i]=='9';
    }
    return s;
}

string M(string s){
    for(int i=0;i<sz(s);i++){
        if('0'<=s[i] and s[i]<'9'){
            s[i]++;
        }else if(s[i]=='9'){
            s[i]='0';
        }
    }
    return s;
}

void solve(){
    string s,t;
    cin >> s >> t;

    for(int i=sz(s)-1;i>=0;i--){
        string u;
        if(s[i]=='J') t = J(t);
        if(s[i]=='C') t = C(t);
        if(s[i]=='E') t = E(t);
        if(s[i]=='A') t = A(t);
        if(s[i]=='P') t = P(t);
        if(s[i]=='M') t = M(t);
    }
    cout << t << endl;
}

int main(){
    int N;
    cin >> N;
    rep(i,N) solve();
}

C++: #include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
#include <cstring>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
#define CLR(mat) memset(mat, 0, sizeof(mat))
typedef long long ll;
int main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n; cin >> n;
  while(n--) {
    string MSer, MS; cin >> MSer >> MS;
    int len = MS.length();
    for(int i = (int)MSer.length() - 1; i >= 0; i--) {
      if(MSer[i] == 'J') {
        for(int i = len - 1; i > 0; i--) {
          swap(MS[i-1], MS[i]);
        }
      }
      if(MSer[i] == 'C') {
        FOR(i,1,len) {
          swap(MS[i-1], MS[i]);
        }
      }
      if(MSer[i] == 'E') {
        string ms1 = "", ms2 = "";
        FOR(i,0,len) {
          if(i < len / 2) {
            ms1 += MS[i];
          } else if(len % 2 == 1 && i == len / 2) {
            ms1 = MS[i] + ms1;
          } else {
            ms2 += MS[i];
          }
        }
        MS = ms2 + ms1;
      }
      if(MSer[i] == 'A') {
        reverse(MS.begin(), MS.end());
      }
      if(MSer[i] == 'P') {
        FOR(i,0,len) {
          if(isdigit(MS[i])){
            int x = MS[i] - '0';
            x = (x - 1 + 10) % 10;
            char y = x + '0';
            MS[i] = y;
          }
        }
      }
      if(MSer[i] == 'M') {
        FOR(i,0,len) {
          if(isdigit(MS[i])){
            int x = MS[i] - '0';
            x = (x + 1) % 10;
            char y = x + '0';
            MS[i] = y;
          }
        }
      }
    }
    cout << MS << endl;
  }
  return 0;
}