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(snake[i] == '~' && 
			i == snake.length() - 1){
			return 1;
		}
	}else if(snake[1] == '^'){
		int i = 2;
		while(snake[i] =='Q' &&
			snake[i + 1] == '='){
			i += 2;
		}
		if(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<vector>
#include<list>
#include<algorithm>
#include<iostream>
#include<string>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
using namespace std;
int main(){
  int i,j;
  int n;
  vector<string> s;
  cin>>n;
  for(i=0;i<n;i++){
    string str;
    cin>>str;
    s.push_back(str);
  }
  for(i=0;i<n;i++){
    if(s[i].find(">'")==0){
      if(s[i].find("~")==s[i].length()-1){
	if(s[i].find("#")!=-1){
	  if(s[i].find("#")-2==s[i].length()-s[i].find("#")-2){
	    int len;
	    string str;
	    str=s[i].substr(2,s[i].find("#")-2);  
	    len=str.length();
	    if(len>0){
	      for(j=0;j<len;j++){
		if(str[j]!='=')
		  break;
	      }
	      if(j==len){
		str=s[i].substr(s[i].find("#")+1,s[i].find("#")-2);
		len=str.length();
		for(j=0;j<len;j++){
		  if(str[j]!='=')
		    break;
		}
		if(j==len){
		  cout<<"A"<<endl;
		  continue;
		}
	      }
	    }
	  }
	}
      }
    }else if(s[i].find(">^")==0){
      if(s[i].find("~~")==s[i].length()-2){
	int len;
	string str;
	str=s[i].substr(2,s[i].length()-4);
	len=str.length();
	if(len>1&&len%2==0){
	  for(j=0;j<len;j+=2){
	    if(str[j]!='Q')
	      break;
	  }
	  if(j==len){
	    for(j=1;j<len;j+=2){
	      if(str[j]!='=')
		break;
	    }
	    if(j==len+1){
	      cout<<"B"<<endl;
	      continue;
	    }
	  }
	}
      }
    }
    cout<<"NA"<<endl;
  }
  return 0;
}

C++: #include <iostream>
#include <string>
#include <sstream>
#include <algorithm>
#include <vector>
#include <utility>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>

using namespace std;

#define rep(i,n) for(int i=0; i<(n); i++)
#define repc(i,s,e) for(int i=(s); i<(e); i++)
#define pb(n) push_back((n))
#define mp(n,m) make_pair((n),(m))
#define all(r) r.begin(),r.end()
#define fi first
#define se second

typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef vector<ll> vl;
typedef vector<vl> vll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;


int main() {
	int n;
	string s;
	cin >> n;
	rep(i, n) {
		cin >> s;
		string ans;
		//cout << s.size() << endl;
		if (s.size() % 2 == 1||s.size()==4) {
			ans = "NA";
		}
		else if (s[0] == '>'&&s[s.size() - 1] == '~') {
			if (s[1] == '\'') {
				ans = "A";
				for (int i = 2; i < s.size() - 1; i++) {
					if (i == s.size() / 2) {
						if (s[i] != '#') {
							ans = "NA";
							break;
						}
					}
					else {
						if (s[i] != '=') {
							ans = "NA";
							break;
						}
					}
				}
			}
			else if (s[1] == '^'&&s[s.size()-2]=='~') {
				ans = "B";
				for (int i = 2; i < s.size() - 2; i += 2) {
					if (s[i] != 'Q' || s[i + 1] != '=') {
						ans = "NA";
						break;
					}
				}
			}
			else ans = "NA";
		}
		else {
			ans = "NA";
		}
		cout << ans << endl;
	}
}

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

int main()
{
	int n;
	cin >> n;
	for(int i=0;i<n;i++){
		bool a=false,b=false;
		string str;
		cin >> str;
		if(str[0] == '>' && str[1] == '\'' && str.size()%2==0){a = true;}
		if(str[0] == '>' && str[1] == '^' && str.size()%2==0){b = true;}
		if(a){
			for(unsigned j=2;j<str.size()-1;j++){
				if(j != (str.size()/2) && str[j] != '='){
					a = false;
					break;
				}
			}
			if(str[str.size()/2] != '#' || str[str.size()-1] != '~')
				a=false;
		}		
		if(b){
			for(unsigned j=2;j<str.size()-3;j+=2){
				if(str[j] != 'Q' || str[j+1] != '='){
					b = false;
					break;
				}
			}
			if(str[str.size()-2] != '~' || str[str.size()-1] != '~')
				b=false;
		}
		if(a)
			cout << "A" << endl;
		else if(b)
			cout << "B" << endl;
		else
			cout << "NA" << endl;
	}
	return 0;
}