#include <iostream>

#include <cstdlib>

#include <vector>

#include <string>

#include <cmath>

#include <algorithm>

#include <map>

using namespace std;

int n, m;

const int len = ;

int num[len];

struct node

{

    int l, r;

    int ll, rr;

    int v;

};

node tr[len << ];

void pushUp(int rt)

{

    tr[rt].v = max(tr[rt << ].v, tr[rt <<  | ].v);

    if (num[tr[rt << ].r] == num[tr[rt <<  | ].l])

        tr[rt].v = max(tr[rt].v, tr[rt << ].rr + tr[rt <<  | ].ll);

    tr[rt].ll = tr[rt << ].ll;

    tr[rt].rr = tr[rt <<  | ].rr;

    if (num[tr[rt].l] == num[tr[rt <<  | ].l])

        tr[rt].ll += tr[rt <<  | ].ll;

    if (num[tr[rt].r] == num[tr[rt << ].r])

        tr[rt].rr += tr[rt << ].rr;

}

void build(int l, int r, int rt)

{

    tr[rt].l = l;

    tr[rt].r = r;

    if (l == r)

    {

        tr[rt].v = ;

        tr[rt].ll = tr[rt].rr = ;

        return;

    }

    int mid = (l + r) >> ;

    build(l, mid, rt << );

    build(mid + , r, rt << |);

    pushUp(rt);

}

int query(int l, int r, int rt)

{

    if (l <= tr[rt].l&&tr[rt].r <= r)

        return tr[rt].v;

    int mid = (tr[rt].l + tr[rt].r) >> ;

    int lr=-, rr=-;

    if (l <= mid)

        lr = query(l, r, rt << );

    if (r > mid)

        rr = query(l, r, rt <<  | );

    int ans = max(lr, rr);

    if (lr != - && rr != -&&num[mid]==num[mid+])

    {

        ans = max(ans, min(tr[rt << ].rr,mid-l+) + min(r-mid,tr[rt <<  | ].ll));

    }

    //if (ans == 4) cout << tr[rt].l << ' ' << tr[rt].r<<' '<<lr<<' '<<rr<< endl;

    return ans;

}

int main()

{

    while (scanf("%d", &n) != EOF)

    {

        if (n == ) break;

        scanf("%d", &m);

        for (int i = ; i <= n; i++)

            scanf("%d", &num[i]);

        build(, n, );

        while (m--)

        {

            int l, r;

            scanf("%d%d", &l , &r);

            printf("%d\n", query(l, r, ));

        }

    }

    return ;

}