#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

using namespace std;


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

//tg: @galebickosikasa

const ll inf = (ll) 4e18;
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());

struct kek {
	int l, r, i;
};

int check (vector<int>& goo, vector<int>& order, vector<kek>& q) {
	int n = sz (goo), m = sz (q);
	vector<int> t (n, m);
	auto moo = goo;
	fr (j, m) {
		auto x = q[order[j]];
		int l = x.l, r = x.r;
		dbg (l);
		dbg (r);
		int L = -1, R = -1;
		int res = 0, sum = 0, left = l - 1;
		fl (i, l, r + 1) {
			sum += moo[i];
			if (sum > res) {
				res = sum;
				L = left + 1;
				R = i;
			}
			if (sum < 0) {
				sum = 0;
				left = i;
			}
		}
		dbg (sum);
		dbg (L);
		dbg (R);
		if (L > -1) fl (i, L, R + 1) {
			t[i] = min (t[i], x.i);
			moo[i] = 0;
		}
	}
	int ans = 0;
	fr (i, n) {
		ans += goo[i] * t[i];
		dbg (t[i]);
	}
	dbg (ans);
	return ans;
}




signed main () {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
	int n, m;
	cin >> n >> m;
	vector<int> goo (n);
	cinv (goo);
	vector<kek> q;
	fr (i, m) {
		int l, r;
		cin >> l >> r;
		--l, --r;
		q.pb ({l, r, i});
	}
	vector<int> a;
	fr (i, m) a.pb (i);
	int ans = check (goo, a, q);
	while (next_permutation (all (a))) {
		ans = min (ans, check (goo, a, q));
	}
	cout << ans;




}