#include <bits/stdc++.h>

int main() {
	int T;
	scanf("%d", &T);
	while (T--) {
		int n, m;
		scanf("%d%d", &n, &m);
		std::vector<int> a(n + 1), cap(n + 1);
		std::vector<int> x(m + 1), t(m + 1), next(m + 1);
		for (int i = 1; i <= n; ++i) {
			scanf("%d", &a[i]);
			cap[i] = a[i];
		}
		std::map<int,int> last;
		std::priority_queue<std::pair<int,int>> q;
		for (int i = 1; i <= m; ++i) {
			scanf("%d%d", &x[i], &t[i]);
			if (last.find(t[i]) != last.end()) {
				next[last[t[i]]] = i;
				last[t[i]] = i;
			} else {
				q.push(std::make_pair(-x[i], t[i]));
				last[t[i]] = i;
			}
		}
		for (int u = 1; u <= n; ++u) {
			if (!last.count(u)) {
				q.push(std::make_pair(-1e9 - 9, u));
			}
		}
		long long pos = 0;
		for (int i = 1; i <= m; ++i) {
			std::vector<int> tmp;
			while (pos < x[i] && !q.empty()) {
				auto [_, u] = q.top(); q.pop();
				if (a[u] > x[i] - pos) {
					a[u] -= x[i] - pos;
					pos = x[i];
					break;
				} else {
					pos += a[u];
					a[u] = 0;
					tmp.emplace_back(u);
				}
			}
			if (pos < x[i]) {
				break;
			}
			a[t[i]] = cap[t[i]];
			for (auto u : tmp) {
				if (next[u] != 0) {
					q.push(std::make_pair(-x[next[u]], next[u]));
				}
			}
		}
		while (!q.empty()) {
			auto [_, u] = q.top(); q.pop();
			pos += a[t[u]];
		}
		printf("%lld\n", pos);
	}
	return 0;
}