Go: package main

import (
	"bufio"
	"os"
	"strconv"
	"strings"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	scanner.Scan()
	n, _ := strconv.Atoi(scanner.Text())
	for i := 0; i < n; i++ {
		ans := "NA"
		scanner.Scan()
		s := scanner.Text()
		if s[:2]==">'" && s[len(s)-1:] == "~" {
			tmp := s[2:len(s)-1]
			t := strings.Split(tmp, "#")
			if len(t) == 2 && len(t[0]) > 0 {
				valid := true
				for _, v := range t[0] {
					if string(v) != "=" {
						valid = false
						break
					}
				}
				if valid && t[0] == t[1] {
					ans = "A"
				}
			}
		} else if s[:2] == ">^" && s[len(s)-2:] == "~~" {
			t := s[2:len(s)-2]
			if len(t) > 0 && len(t)%2 == 0 {
				valid := true
				for i := 0; i < len(t); i += 2 {
					if t[i:i+2] != "Q=" {
						valid = false
						break
					}
				}
				if valid {
					ans = "B"
				}
			}
 		}
		fmt.Println(ans)
	}
}

C++: 
//include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <tuple>

using namespace std;

//conversion
//------------------------------------------
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//math
//-------------------------------------------
template<class T> inline T sqr(T x) {return x*x;}

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;

//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define MT make_tuple
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

//constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI  = acos(-1.0);
const int DX[] = {0, 1, 0, -1};
const int DY[] = {-1, 0, 1, 0};

//other
//--------------------------------------------
#define RANGE(a, c, b) ((a <= b) && (b < c))

//clear memory
#define CLR(a) memset((a), 0 ,sizeof(a))

//debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

int solve(string snake){
	if(snake[0] != '>') return 0;
	if(snake[1] == '\''){
		int i = 2;
		while(snake[i] == '='){
			i++;
		}
		if(snake[i] != '#') return 0;
		int length = i - 2;
		i++;
		while(snake[i] == '='){
			i++;
		}
		int length2 = i -3 - length;
		if(length2 != length) return 0;
		if(length > 0 &&
			snake[i] == '~' && 
			i == snake.length() - 1){
			return 1;
		}
	}else if(snake[1] == '^'){
		int i = 2;
		int length = 0;
		while(snake[i] =='Q' &&
			snake[i + 1] == '='){
			i += 2;
			length++;
		}
		if(length > 0 &&
			snake[i] == '~' &&
			snake[i + 1] == '~' &&
			i + 1 == snake.length() - 1){
			return 2;
		}
	}
	return 0;
}

int main(int argc, char const *argv[])
{
	int n;
	cin >> n;
	REP(i, n){
		string snake;
		cin >> snake;
		string ans;
		switch(solve(snake)){
			case 0:
			ans = "NA";
			break;

			case 1:
			ans = "A";
			break;

			case 2:
			ans = "B";
			break;
		}
		cout << ans << endl;
	}
	
	return 0;
}

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

using namespace std;

int main()
{
	int n;
	cin >> n;
	for(int D = 0; D < n; ++D){
		string s;
		cin>>s;
		
		if(s.compare(0,2,">'")== 0){
			int bef_eq = 0;
			int aft_eq = 0;
			int shp = 0;
			int pos_shp = 0;
			int pos_tld = 0;

			for(unsigned int i = 2; i < s.length(); ++i ){
				switch( s[i] ){
					case '=':
						if( shp == 0 )
							++bef_eq;
						else
							++aft_eq;
						break;
					case '#':
						shp++;
						break;
					case '~':
						if( i != s.length() - 1 )
							shp = 2;
						pos_tld = i;
						break;
					default:
						shp = 2;
						break;
				}
			}
			if( bef_eq && aft_eq && pos_tld && bef_eq == aft_eq && shp == 1 )
				cout << "A\n";
			else
				cout << "NA\n";
		}else if(s.compare(0,2,">^")==0){
			int cnt_qeq = 0;
			int pos_tltl = 0;
			bool invalid = false;
			
			if( s.length() <= 2 || s.length() % 2 == 1 )
				invalid = true;
			
			for(unsigned int i = 2; i < s.length() && !invalid; i+=2){
				if( s.compare(i,2,"Q=") == 0 )
					++cnt_qeq;
				else if( s.compare(i,2,"~~") == 0 ){
					pos_tltl = i;
					break;
				}else
					invalid = true;
			}
			if( pos_tltl != s.length() - 2 ){
				invalid = true;
			}
			if( invalid )
				cout << "NA\n";
			else
				cout << "B\n";
		}else{
			cout <<"NA\n";
		}
	}
	return 0;
}

C++: #include<bits/stdc++.h>
#define rep(i,n)for(int i=0;i<n;i++)
using namespace std;

int main() {
	int n; scanf("%d", &n);
	rep(i, n) {
		string s; cin >> s;
		if (s.size() < 4 || s.size() % 2 == 1) {
			puts("NA");
			continue;
		}
		if (s[0] == '>'&&s[1] == '\''&&s[s.size() - 1] == '~') {
			int cnt = 0;
			bool flag = false;
			bool ok = false;
			for (int i = 2; i < s.size() - 1; i++) {
				if (s[i] != '='&&s[i] != '#') { puts("NA"); goto g; }
				if (flag&&s[i] == '#') { puts("NA"); goto g; }
				if (s[i] == '#')flag = true;
				else {
					ok = true;
					if (flag)cnt--;
					else cnt++;
				}
			}
			if (!ok) { puts("NA"); goto g; }
			puts(cnt ? "NA" : "A");
		}
		else if (s[0] == '>'&&s[1] == '^'&&s[s.size() - 2] == '~'&&s[s.size() - 1] == '~') {
			if (s.size() == 4) { puts("NA"); goto g; }
			for (int i = 2; i < s.size() - 2; i += 2) {
				if (s[i] != 'Q' || s[i + 1] != '=') {
					puts("NA"); goto g;
				}
			}
			puts("B");
		}
		else puts("NA");
	g:;
	}
}