#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;
typedef long long ll;
typedef unsigned long long ull;
const int N = 2000086, MOD = 1e9 + 7, INF = 0x3f3f3f3f;
ll res;
int n, m, cnt, w[N];

int p[N];
ll sz[N];
int find(int x) {
	if (p[x] != x) p[x] = find(p[x]);
	return p[x];
}

int main() {
	int T;
	// cin >> T;
	T = 1;
	while (T--) {
		cin >> n;
		p[n + 1] = n + 1, w[n + 1] = sz[n + 1] = 0;
		for (int i = 1; i < n + 1; i++) {
			scanf("%d", w + i);
			p[i] = i;
			sz[i] = w[i];
			if (i > 1 && w[i] && w[i - 1]) {
				int j = find(i - 1);
				sz[j] += sz[i];
				p[i] = j;
			}
		}
		cin >> m;
		while (m--) {
			int a, b;
			scanf("%d%d", &a, &b);
			if (!w[a]) {
				printf("%lld\n", sz[find(a - 1)] + sz[find(a + 1)] + b);
			} else {
				printf("%lld\n", sz[find(a)] - w[a] + b);
			}
		}
	}
	return 0;
}