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 <algorithm>
#include <iostream>

using namespace std;

string rotate_left (string s) {
    return s.substr(1, s.size() - 1) + s.substr(0, 1);
}

string rotate_right (string s) {
    return s.substr(s.size() - 1, 1) + s.substr(0, s.size() - 1);
}

string swap_half (string s) {
    return s.substr(s.size() / 2, s.size() - s.size() / 2) + s.substr(0, s.size() / 2);
}

string rev(string s) {
    reverse(begin(s), end(s));
    return s;
}

string inc_dig (string s) {
    string ret = "";
    for (char c : s) {
        if(isdigit(c)) {
            ret += ((c - '0') + 1) % 10 + '0';
        } else {
            ret += c;
        }
    }
    return ret;
}

string dec_dig (string s) {
    string ret = "";
    for (char c : s) {
        if(isdigit(c)) {
            ret += ((c - '0') + 9) % 10 + '0';
        } else {
            ret += c;
        }
    }
    return ret;
}

int main() {
    int n;
    cin >> n;
    while (n--) {
        string opers, s;
        cin >> opers >> s;
        for (auto op = opers.rbegin(); op != opers.rend(); ++op) {
            if(*op == 'J') {
                s = rotate_right(s);
            } else if (*op == 'C') {
                s = rotate_left(s);
            } else if (*op == 'E') {
                s = swap_half(s);
            } else if (*op == 'A') {
                s = rev(s);
            } else if (*op == 'P') {
                s = dec_dig(s);
            } else if (*op == 'M') {
                s = inc_dig(s);
            }
        }
        cout << s << endl;
        
    }
    return 0;
}

C++: #include "bits/stdc++.h"
#define pb push_back
#define mt make_tuple
#define all(a) (a).begin(),(a).end()
#define frep(i,a,n) for(int i=(a);i<(n);++i)
#define rep(i, n) for(int i=0;i<(n);++i)
#define rrep(i, n) for(int i=n-1;i>=0;--i)
#define debug(x) cout << #x << " : " << x << " ------------ " << endl;
using namespace std;
int main()
{
    int n;
    cin >> n;
    while (n--) {
        string o;
        cin >> o;
        string m;
        cin >> m;
        
        rep (i, o.length()) {
            switch (o[i]) {
                case 'A':
                    reverse(all(m));
                    break;
                case 'J':
                    rotate(m.rbegin(), m.rbegin() + 1, m.rend());
                    break;
                case 'C':
                    rotate(m.begin(), m.begin() + 1, m.end());
                    break;
                case 'P': {
                    auto it = m.begin();
                    while (it != m.end()) {
                        if (isdigit(*it) && --(*it) < '0') *it = '9';
                        ++it;
                    }
                    break; }
                case 'M': {
                    auto it = m.begin();
                    while (it != m.end()) {
                        if (isdigit(*it) && ++(*it) > '9') *it = '0';
                        ++it;
                    }
                    break; }
                case 'E': {
                    int len = m.length();
                    string f = m.substr(0, len / 2);
                    char mdl = m.length() % 2 ? m[len / 2] : 0;
                    string b = m.substr((len + 1) / 2);
                    m = b + mdl + f;
                    break; }
                default:
                    break;
            }
        }
        cout << m << endl;
    }
    return EXIT_SUCCESS;
}