#include<bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define all(c) (c).begin(),(c).end()
#define pb push_back
#define dbg(...) do{cerr<<__LINE__<<": ";dbgprint(#__VA_ARGS__, __VA_ARGS__);}while(0);

using namespace std;

namespace std{template<class S,class T>struct hash<pair<S,T>>{size_t operator()(const pair<S,T>&p)const{return ((size_t)1e9+7)*hash<S>()(p.first)+hash<T>()(p.second);}};template<class T>struct hash<vector<T>>{size_t operator()(const vector<T> &v)const{size_t h=0;for(auto i : v)h=h*((size_t)1e9+7)+hash<T>()(i)+1;return h;}};}
template<class T>ostream& operator<<(ostream &os, const vector<T> &v){os<<"[ ";rep(i,v.size())os<<v[i]<<(i==v.size()-1?" ]":", ");return os;}template<class T>ostream& operator<<(ostream &os,const set<T> &v){os<<"{ "; for(const auto &i:v)os<<i<<", ";return os<<"}";}
template<class T,class U>ostream& operator<<(ostream &os,const map<T,U> &v){os<<"{";for(const auto &i:v)os<<" "<<i.first<<": "<<i.second<<",";return os<<"}";}template<class T,class U>ostream& operator<<(ostream &os,const pair<T,U> &p){return os<<"("<<p.first<<", "<<p.second<<")";}
void dbgprint(const string &fmt){cerr<<endl;}template<class H,class... T>void dbgprint(const string &fmt,const H &h,const T&... r){cerr<<fmt.substr(0,fmt.find(","))<<"= "<<h<<" ";dbgprint(fmt.substr(fmt.find(",")+1),r...);}
typedef long long ll;typedef vector<int> vi;typedef pair<int,int> pi;const int inf = (int)1e9;const double INF = 1e12, EPS = 1e-9;

int main(){
	cin.tie(0); cin.sync_with_stdio(0);
	int n;
	int cs = 0;
	while(cin >> n, n){
		vi a(n), b(n);
		rep(i, n) cin >> a[i]; sort(all(a), greater<int>());
		rep(i, n) cin >> b[i]; sort(all(b), greater<int>());
		/*
		if(++cs != 2) continue;
		dbg(a);
		dbg(b);
		
		deque<int> d;
		*/
		for(int i = 0, j = 0; i < n - 1; i++){
			/*
			if(d.size()){
				assert(d.front() >= a[i]);
				if(d.front() > a[i]) { d.pop_front(); continue; }
			}
			if(a[i] == b[j]){
				d.pb(b[j++]);
				continue;
			}
			*/
			
			if(a[i] <= b[j])  j++;
			
			if((i+1) / 2 < i+1 - j){
				/*
				dbg(i, j);
				rep(k, d.size()) cerr<<d[k]<<" "; cerr<<endl;
				*/
				cout << i+1 << endl;
				goto END;
			}
		}
		cout << "NA" << endl;
		END:;
	}
	return 0;
}
