// iostream is too mainstream
#include <cstdio>
// bitch please
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <cmath>
#include <iomanip>
#define dibs reserve
#define OVER9000 1234567890
#define ALL_THE(CAKE,LIE) for(auto LIE =CAKE.begin(); LIE != CAKE.end(); LIE++)
#define tisic 47
#define soclose 1e-8
#define chocolate win
// so much chocolate
#define patkan 9
#define ff first
#define ss second
#define abs(x) ((x < 0)?-(x):x)
#define uint unsigned int
#define dbl long double
using namespace std;
// mylittledoge

int main() {
	cin.sync_with_stdio(0);
	cin.tie(0);
	int N,K,a;
	cin >> N >> K;
	multiset<int> S1,P;
	for(int i =0; i < N; i++) {
		cin >> a;
		S1.insert(a);} // 5*a
	for(int i =0; i < K; i++) {
		cin >> a;
		P.insert(a);} // 5*a

	int ans =N;
	while(!S1.empty()) {
		if(P.empty()) {cout << "NIE\n"; return 0;}
		a =*S1.rbegin();
		S1.erase(--S1.end());
		if(*P.rbegin() >= 5*a) {
			P.erase(--P.end());
			continue;}
		ans++;
		auto it =P.lower_bound(3*a);
		if(it == P.end()) {cout << "NIE\n"; return 0;}
		P.erase(it);
		it =P.lower_bound(2*a);
		if(it == P.end()) {cout << "NIE\n"; return 0;}
		P.erase(it);}

	cout << ans << "\n";
	return 0;}

// look at my code
// my code is amazing