#include "bits/stdc++.h"

using namespace std;

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    vector<int> a(n - 1);
    vector<long long> f(n - 1);
    for (int i = 0; i + 1 < n; i++) {
        cin >> a[i];
        for (int j = i; j < n; j = j | (j + 1)) {
            f[j] += a[i];
        }
    }
    auto ask = [&] () {
        long long sum = 0;
        for (int i = n - 2; i >= 0; i = (i & (i + 1)) - 1) {
            sum += f[i];
        }
        int pos = 0;
        long long cur = 0;
//        for (auto& x : f) cout << x << " "; cout << endl;
        for (int j = 20; j >= 0; j--) {
            if (pos + (1 << j) >= n) {
                continue;
            }
            if (cur + f[pos + (1 << j) - 1] > sum / 2) {
                continue;
            }
            cur += f[pos + (1 << j) - 1];
            pos += (1 << j);
        }
        long long ans = abs(sum - cur - cur);
        ans = min(ans, abs(sum - (cur + a[pos]) - (cur + a[pos])));
        cout << ans << '\n';
    };
    ask();
    int q;
    cin >> q;
    while (q--) {
        int i, x;
        cin >> i >> x;
        i--;
        for (int j = i; j < n; j = j | (j + 1)) {
            f[j] += x - a[i];
        }
        a[i] = x;
        ask();
    }
}