// #pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.1,sse4.2,popcnt,abm,mmx,avx")
// #pragma comment(linker, "/stack:200000000"]

#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <unordered_set>
#include <unordered_map>
#include <set>
#include <map>
#include <queue>
#include <deque>
#include <bitset>
#include <stack>
#include <random>
#include <fstream>
#include <sstream>
#include <chrono>

#define fi first
#define se second
#define pb push_back
#define ll long long
#define ld long double
#define hm unordered_map
#define pii pair<int, int>
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define cinv(v) for (auto& x: v) cin >> x
#define fr(i, n) for (int i = 0; i < n; ++i)
#define fl(i, l, n) for (int i = l; i < n; ++i)

#define int ll

template <typename T1, typename T2> inline bool chkmin(T1 &x, const T2 &y) {if (x > y) {x = y; return 1;} return 0;}
template <typename T1, typename T2> inline bool chkmax(T1 &x, const T2 &y) {if (x < y) {x = y; return 1;} return 0;}

using namespace std;

#ifdef __LOCAL
	#define dbg(x) cerr << #x << " : " << x << '\n'
	const int maxn = 2e5 + 20;
#else
	#define dbg(x)
	const int maxn = 2e5 + 20;
#endif

//tg: @galebickosikasa

ostream& operator << (ostream& out, vector<int>& v) {
	for (auto& x: v) out << x << ' ';
	return out;
}

ostream& operator << (ostream& out, pii& v) {
	out << v.fi << ", " << v.se;
	return out;
}

istream& operator >> (istream& in, pii& a) {
	in >> a.fi >> a.se;
	return in;
}

const ll inf = (ll) 2e9;
const ld pi = asin (1) * 2;
const ld eps = 1e-8;
const ll mod = (ll)1e9 + 7;
const ll ns = 97;

mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

int d[maxn], dist[maxn];

int bit (int msk, int i) {
	return (msk>>i) & 1;
}

signed main () {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	int n, m;
	cin >> n >> m;
	vector<int> w (n);
	cinv (w);
	vector<pii> moo (m);
	cinv (moo);
	int mx = 0, mn = inf;
	for (auto& x: w) chkmax (mx, x);
	for (auto& x: moo) chkmin (mn, x.se);
	if (mx > mn) {
		cout << -1;
		exit (0);
	}
	int M = (1<<n);
	fl (msk, 1, M) {
		int s = 0;
		fr (i, n) {
			if (bit (msk, i)) {
				s += w[i];
			}
		}
		d[msk] = s;
	}
	fr (i, m) {
		fl (msk, 1, M) {
			if (d[msk] <= moo[i].se) continue;
			int res = inf * inf;
			// res = d[msk] / moo[i].se * moo[i].fi;
			fr (j, n) {
				if (bit (msk, j)) {
					chkmin (res, dist[msk^(1<<j)] + moo[i].fi);
				}
			}
			chkmax (dist[msk], res);
			// dbg (msk);
			// dbg (dist[msk]);
		}
	}
	cout << dist[M - 1] << '\n';








}