#include "bits/stdc++.h"

typedef long long ll;

using namespace std;
const int N = 2e5 + 10;

int main() {
    int T;
    scanf("%d", &T);
    while (T--) {
        int n, m;
        scanf("%d%d", &n, &m);
        vector<int> a(n + 1), x(m + 2), t(m + 2);
        t[m + 1] = n + 1;
        int asdf = 0;
        for (int i = 1; i <= n; i++)scanf("%d", &a[i]);
        for (int i = 1; i <= m; i++)scanf("%d%d", &x[i], &t[i]);
        vector<int> nxt(m + 1), col(n + 1);
        vector<ll> leftpower(n + 2);
        for (int i = 1; i <= n; i++)leftpower[i] = a[i];
        for (int i = m; i >= 1; i--) {
            if (col[t[i]] == 0)nxt[i] = -1;
            else nxt[i] = col[t[i]];
            col[t[i]] = i;
        }
        priority_queue<int, vector<int>, greater<int> > q;
        for (int i = 1; i <= n; i++) {
            if (col[i]) {
                q.push(col[i]);
//                printf("push=%d\n", i);
            } else {
                leftpower[n + 1] += a[i];
                leftpower[i] = 0;
            }
        }
        ll nowpos = 0;
        q.push(m + 1);
        for (int i = 1; i <= m; i++) {
            while (!q.empty()) {
                int p = q.top();//下一个充电站位置
                q.pop();
//                printf("p=%d\n", p);
                if (nowpos + leftpower[t[p]] >= x[i])leftpower[t[p]] -= x[i] - nowpos, nowpos = x[i];
                else nowpos += leftpower[t[p]], leftpower[t[p]] = 0;
                if (nowpos == x[i])break;
            }
            if (nowpos < x[i])break;
            if (nxt[i] != -1)q.push(nxt[i]), leftpower[t[i]] = a[t[i]];
            else {
                leftpower[n + 1] += a[t[i]];
                leftpower[t[i]] = 0;
            }
            q.push(m + 1);
//            for (int j = 1; j <= n + 1; j++) {
//                printf("nowpos=%d leftpower[%d]=%d\n", nowpos, j, leftpower[j]);
//            }
            if (i == m) {
                for (int j = 1; j <= n + 1; j++) {
                    nowpos += leftpower[j];
//                    printf("leftpower[%d]=%d\n", j, leftpower[j]);
                }
            }
        }

        printf("%lld\n", nowpos);
    }
    return 0;
}
/*
 *
 2
 3 1
 3 3 3
 8 1
 2 2
 5 2
 1 2
 2 1
 *
 */