#include <bits/stdc++.h>
using namespace std;
#define Loop(x,l,r) for (ll x = ll(l); x < ll(r); ++x)
#define LoopR(x,l,r) for (ll x = ll(r)-1; x >= ll(l); --x)
#define Looc(x,l,r) for (ll x = ll(l); x <= ll(r); ++x)
#define LoocR(x,l,r) for (ll x = ll(r); x >= ll(l); --x)
#define int ll
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#ifndef DB
#define DB 0
#define endl '\n'
#endif
#define debugl(l) if constexpr ((l) < DB)
#define debug debugl(0)

struct DSU {
	vector<int> par;
	vector<ll> sum;
	int n;

	void init(int sz) {
		n = sz;
		par.assign(n, -1);
		sum.assign(n, 0);
	}

	int rt(int v) { return par[v] == -1? v: (par[v] = rt(par[v])); }

	void unite(int v, int u) {
		v = rt(v);
		u = rt(u);
		if (v != u) {
			par[u] = v;
			sum[v] += sum[u];
		}
	}

	void add(int v, ll x) {
		v = rt(v);
		sum[v] += x;
	}

	ll get(int v) { return sum[rt(v)]; }
};

void solve()
{
	int n;
	cin >> n;
	vector<ll> val(n);
	for (auto &x : val)
		cin >> x;

	DSU dsu;
	dsu.init(n);

	auto tryu = [&](int i) {
		if (!val[i])
			return;
		if (0 <= i-1 && val[i-1])
			dsu.unite(i-1, i);
		if (i+1 < n && val[i+1])
			dsu.unite(i+1, i);
	};
	auto getu = [&](int i) {
		if (val[i])
			return dsu.get(i);
		ll ans = 0;
		if (0 <= i-1)
			ans += dsu.get(i-1);
		if (i+1 < n)
			ans += dsu.get(i+1);
		return ans;
	};

	Loop (i,0,n) {
		dsu.add(i, val[i]);
		tryu(i);
	}

	int q;
	cin >> q;
	while (q--) {
		int i, x;
		cin >> i >> x;
		i--;

		cout << getu(i) + x - val[i] << '\n';
	}
}

signed main()
{
	cin.tie(0) -> sync_with_stdio(false);
	int t = 1;
	//cin >> t;
	while (t--)
		solve();
}