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#include<cstdio>
#include<iostream>
#include<algorithm>
#include<map>
using namespace std;

map<int, int> a;

int main()
{
	int n, m;
	long long ans = 0;
	cin >> n >> m;
	for (int i = 1; i <= n; i++)
	{
		int q;
		cin >> q;
		a[q]++;
	}
	for (int i = 1; i <= m; i++)
	{
		int b, c, cnt = 0;
		cin >> b >> c;
		for (auto x: a)
		{
			if (x.first >= c) break;
			else if (b == 0) break;
			else if (b < x.second)
			{
				cnt += b;
				a[x.first] = x.second - b;
				b = 0;
				break;
			}
			else if (b == x.second)
			{
				cnt += b;
				b = 0;
				if (a.count(x.first)) a.erase(x.first);
				break;
			}
			else if (b > x.second)
			{
				cnt += x.second;
				b -= x.second;
				if (a.count(x.first)) a.erase(x.first);
			}
		}
		a[c] += cnt;
	}
	for (auto x: a)
	{
		ans += x.first * 1ll * x.second;
	}
	cout << ans;
	return 0;
}