#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
using namespace std;

const int INF = (int)1e7 + 10;
const int N = 500500;
int n;
int a[N];
int ans[N];
int deg[N];
int q[N];
int C;
int topQ;

int main()
{
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);

    scanf("%d", &n);
    for (int i = 0; i < n; i++)
        scanf("%d", &a[i]);
    C = a[n - 1];
    int it = 0;
    for (int x = 0; x <= C; x++)
    {
        ans[x] = INF;
        if (it < n && a[it] < x) it++;
        deg[x] = n - it;
        if (deg[x] == 1)
        {
            ans[x] = 1;
            q[topQ++] = x;
        }
    }
    for (int k = 0; k < topQ; k++)
    {
        int x = q[k];
        it = n - 1;
        while(it >= 0 && x <= a[it])
        {
            int y = a[it] - x;
            if (ans[y] == INF)
            {
                deg[y]--;
                if (deg[y] == 1)
                {
                    ans[y] = ans[x] + 1;
                    q[topQ++] = y;
                }
            }
            it--;
        }
    }
    int m;
    scanf("%d", &m);
    while(m--)
    {
        int x, y;
        scanf("%d%d", &x, &y);
        int res = min(ans[x], ans[y]);
        if (res == INF)
            printf("-1\n");
        else
            printf("%d\n", res);
    }

    return 0;
}