using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    static int[] NMi => ReadLine().Split().Select(c => int.Parse(c) - 1).ToArray();
    static int[][] NMap(int n) => Enumerable.Repeat(0, n).Select(_ => NMi).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var a = NList;
        var q = NN;
        var map = NArr(q);
        var sum = new long[n];
        for (var i = 0; i < n; ++i) sum[i] = a[i];
        var uf = new UnionFindTree(n);
        for (var i = 0; i + 1 < n; ++i)
        {
            if (a[i] > 0 && a[i + 1] > 0)
            {
                var ar = uf.GetRoot(i);
                var br = uf.GetRoot(i + 1);
                uf.Unite(i, i + 1);
                var nr = uf.GetRoot(i);
                sum[nr] = sum[ar] + sum[br];
            }
        }
        var ans = new long[q];
        for (var i = 0; i < q; ++i)
        {
            var x = map[i][0] - 1;
            var b = map[i][1];
            if (a[x] == 0)
            {
                ans[i] = b;
                if (x > 0) ans[i] += sum[uf.GetRoot(x - 1)];
                if (x + 1 < n) ans[i] += sum[uf.GetRoot(x + 1)];
            }
            else
            {
                ans[i] = sum[uf.GetRoot(x)] + b - a[x];
            }
        }
        WriteLine(string.Join("\n", ans));
    }
    class UnionFindTree
    {
        int[] roots;
        public UnionFindTree(int size)
        {
            roots = new int[size];
            for (var i = 0; i < size; ++i) roots[i] = -1;
        }
        public int GetRoot(int a)
        {
            if (roots[a] < 0) return a;
            return roots[a] = GetRoot(roots[a]);
        }
        public bool IsSameTree(int a, int b)
        {
            return GetRoot(a) == GetRoot(b);
        }
        public bool Unite(int a, int b)
        {
            var x = GetRoot(a);
            var y = GetRoot(b);
            if (x == y) return false;
            if (-roots[x] < -roots[y]) { var tmp = x; x = y; y = tmp; }
            roots[x] += roots[y];
            roots[y] = x;
            return true;
        }
        public int GetSize(int a)
        {
            return -roots[GetRoot(a)];
        }
    }
}