public static void Run()
{
using (FastScanner fs = new FastScanner(new BufferedStream(Console.OpenStandardInput())))
using (StreamWriter writer = new StreamWriter(new BufferedStream(Console.OpenStandardOutput())))
{
int n = fs.NextInt(), m = fs.NextInt(), bsize = (int)Math.Ceiling(Math.Sqrt(n));
int[] a = new int[n];
for (int i = 0; i < n; i++)
{
a[i] = fs.NextInt();
}
Query[] queries = new Query[m];
for (int i = 0; i < m; i++)
{
int left = fs.NextInt() - 1, right = fs.NextInt() - 1;
queries[i] = new Query { Id = i, Left = left, Right = right, Block = left / bsize };
}
queries = queries.OrderBy(q => q.Block).ThenBy(q => q.Right).ToArray();
counts = new Dictionary<int, int>();
int l = 0, r = 0;
Add(a[0]);
int[] answers = new int[m];
foreach (Query q in queries)
{
while (r < q.Right)
{
r++;
Add(a[r]);
}
while (r > q.Right)
{
Remove(a[r]);
r--;
}
while (l < q.Left)
{
Remove(a[l]);
l++;
}
while (l > q.Left)
{
l--;
Add(a[l]);
}
answers[q.Id] = answer;
}
for (int i = 0; i < m; i++)
{
writer.WriteLine(answers[i]);
}
}
}
public static void Run()
{
using (FastScanner fs = new FastScanner(new BufferedStream(Console.OpenStandardInput())))
using (StreamWriter writer = new StreamWriter(new BufferedStream(Console.OpenStandardOutput())))
{
int n = fs.NextInt();
int[] a = Array.ConvertAll(fs.ReadLine().Split(), Convert.ToInt32);
int m = fs.NextInt();
Query[] queries = new Query[m];
for (int i = 0; i < m; i++)
{
queries[i] = new Query { Id = i, Left = fs.NextInt() - 1, Right = fs.NextInt() - 1};
}
queries = queries.OrderBy(q => q.Right).ToArray();
int[] xor = new int[n];
int[] answers = new int[m];
xor[0] = a[0];
for (int i = 1; i < n; i++)
{
xor[i] = xor[i - 1] ^ a[i];
}
Dictionary<int, int> lastPos = new Dictionary<int, int>();
XorSegmentTreeFast distincts = new XorSegmentTreeFast(new int[n]);
int r = -1;
foreach (Query q in queries)
{
while (r < q.Right)
{
r++;
if (lastPos.ContainsKey(a[r]))
{
distincts.Update(lastPos[a[r]], 0);
lastPos[a[r]] = r;
}
else
{
lastPos.Add(a[r], r);
}
distincts.Update(r, a[r]);
}
answers[q.Id] = q.Left > 0 ? xor[q.Right] ^ xor[q.Left - 1] : xor[q.Right];
answers[q.Id] ^= distincts.QueryXor(q.Left, q.Right);
}
for (int i = 0; i < m; i++)
{
writer.WriteLine(answers[i]);
}
}
}