#include <string.h>
#include <stdio.h>

struct rec_tree
{
	int up, l, r;
	rec_tree():up(-1), l(-1), r(-1){}
};
struct rec_query
{
	int u, qk, e;
};
const int 	maxn = 100005;
rec_tree	tree[maxn];
rec_query	query[3*maxn];
int		ans[maxn], head[maxn], a[maxn], nset[maxn], w[maxn], ql[maxn], qr[maxn], father[maxn];
int 		tot, n, m, q, root;
bool		vis[maxn];
void init()
{
	memset(head, -1, sizeof(head));
	memset(vis, false, sizeof(vis));
	tot = 0;
	m = 0;
}

void add_query(int u1, int v1, int kv)
{
	query[tot].u = v1; query[tot].qk = kv; query[tot].e = head[u1]; head[u1] = tot++;
	query[tot].u = u1; query[tot].qk = kv; query[tot].e = head[v1]; head[v1] = tot++;
}
void readd()
{
	for (int i = 0; i < n; ++i) scanf("%d", &a[i]);
	int j, k = 0;
	while (k < n)
	{
		j = k;
		while (j < n && a[j] == a[j+1]) nset[j++] = m;
		nset[j] = m;
		w[m++] = j-k+1;
		k = j+1;
	}
	for (int i = 0; i < q; ++i)
	{
		scanf("%d%d", &ql[i], &qr[i]);
		if (nset[ql[i]-1]+1 < nset[qr[i]-1]) 
			add_query(nset[ql[i]-1]+1, nset[qr[i]-1]-1, i);
	}
	for (int i = 0; i < m; ++i)
		tree[i] = rec_tree();
	int l = 0, tp;
	root = 0;
	for (int i = 1; i < m; ++i)
	{
		tree[l].r = i;
		tree[i].up = l;
		while (l != -1 && w[i] > w[l])
		{
			tp = tree[l].up;
			tree[i].up = tree[l].up; 
			if (tree[l].up != -1) tree[tree[l].up].r = i;
			else root = i;
			tree[l].up = i;
			if (tree[i].l == -1)
			{
				tree[i].l = l;
				tree[l].r = -1;
			}
			else {
				k = tree[i].l; tree[i].l = l;
				tree[l].r = k; tree[k].up = l;
			}
			l = tp;
		}
		l = i;
	}
	for (int i = 0; i < m; ++i) father[i] = i;
}

int find_fa(int p)
{
	int t = p, kp = p;
	for (; p != father[p]; p = father[p]);
	for (; kp != p; t = kp)
	{
		kp = father[t];
		father[t] = p;
	}
	return p;
}

void tarjan_lca(int p)
{
	if (tree[p].l != -1)
	{
		tarjan_lca(tree[p].l);
		father[tree[p].l] = p;
	}
	if (tree[p].r != -1)
	{
		tarjan_lca(tree[p].r);
		father[tree[p].r] = p;
	}
	vis[p] = true;
	int tp = head[p];
	while (tp != -1)
	{
		if (vis[query[tp].u]) 
			ans[query[tp].qk] = w[find_fa(query[tp].u)];
		tp = query[tp].e;
	}
}
		
int main()
{
	scanf("%d", &n);
	while (n != 0)
	{
		scanf("%d", &q);
		init();
		readd();

		tarjan_lca(root);
		for (int i = 1; i < m; ++i)
			w[i] += w[i-1];
		int tm, maxt;
		for (int i = 0; i < q; ++i)
		{
			if (nset[ql[i]-1] == nset[qr[i]-1])
				printf("%d\n", qr[i] - ql[i]+1);
			else if (nset[ql[i]-1]+1 == nset[qr[i]-1])
			{
				maxt = w[nset[ql[i]-1]]-ql[i]+1;
				if (qr[i]-w[nset[qr[i]-1]-1] > maxt) maxt = qr[i]-w[nset[qr[i]-1]-1];
				printf("%d\n", maxt);/*std::max(w[nset[ql[i]-1]]-ql[i]+1, qr[i]-w[nset[qr[i]-1]-1]*/
			}
			else {
				tm = w[nset[ql[i]-1]]-ql[i]+1;
				if (qr[i]-w[nset[qr[i]-1]-1] > tm) tm = qr[i]-w[nset[qr[i]-1]-1];
					//std::max(w[nset[ql[i]-1]]-ql[i]+1, qr[i]-w[nset[qr[i]-1]-1]);
				if (ans[i] > tm) tm = ans[i];
				printf("%d\n", tm);/*std::max(tm, ans[i])*/
			}
		}
		scanf("%d",&n);
	}
}