#include <bits/stdc++.h>
using namespace std;

const int MAXN = 200000;

int n;
int a[MAXN + 1];

struct Node {
    int max_subseg_sum, max_prefix_sum, max_suffix_sum, seg_sum;
    Node() {}
    Node(int x) {
        max_subseg_sum = max_prefix_sum = max_suffix_sum = max(0, x);
        seg_sum = x;
    }
    Node(const Node& l, const Node& r) {
        max_subseg_sum = max({l.max_subseg_sum, r.max_subseg_sum, l.max_suffix_sum + r.max_prefix_sum});
        max_prefix_sum = max({l.max_prefix_sum, l.seg_sum + r.max_prefix_sum});
        max_suffix_sum = max({r.max_suffix_sum, r.seg_sum + l.max_suffix_sum});
        seg_sum = l.seg_sum + r.seg_sum;
    }
};

Node tree[4 * MAXN];

void build(int node, int start, int end) {
    if (start == end) {
        tree[node] = Node(a[start]);
    } else {
        int mid = (start + end) / 2;
        build(2 * node, start, mid);
        build(2 * node + 1, mid + 1, end);
        tree[node] = Node(tree[2 * node], tree[2 * node + 1]);
    }
}

void update(int node, int start, int end, int pos, int val) {
    if (start == end) {
        tree[node] = Node(val);
    } else {
        int mid = (start + end) / 2;
        if (pos <= mid) {
            update(2 * node, start, mid, pos, val);
        } else {
            update(2 * node + 1, mid + 1, end, pos, val);
        }
        tree[node] = Node(tree[2 * node], tree[2 * node + 1]);
    }
}

int main() {
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }

    build(1, 1, n);

    int q;
    cin >> q;
    while (q--) {
        int l, r;
        cin >> l >> r;

        update(1, 1, n, l, *max_element(a + l, a + r + 1));

        cout << tree[1].max_subseg_sum << '\n';
    }

    return 0;
}