#include <fstream>
#include <algorithm>

using namespace std;

struct aww
{
    long long st, dr, mij;
    int lst, ldr, lg;

    aww ()
    {
        st = dr = mij = -20000000000000000LL;
        lst = ldr = lg = 0;
    }

    aww (long long x)
    {
        st = dr = mij = x;
        lst = ldr = lg = 1;
    }

} arb[400010];

int n, m;

inline aww unite (aww a, aww b)
{
    aww sol;
    sol.mij = a.dr + b.st;

    if (a.ldr == a.lg) sol.st = sol.mij, sol.lst = a.lg + b.lst;
    if (b.lst == b.lg) sol.dr = sol.mij, sol.ldr = b.lg + a.ldr;

    aww rez;
    rez.lg = a.lg + b.lg;

    rez.lst = a.lst;
    rez.st = a.st;
    if (a.lst == a.lg)
        if (rez.st < rez.st + b.st)
            rez.st += b.st,
            rez.lst += b.lst;

    rez.ldr = b.ldr;
    rez.dr = b.dr;
    if (b.ldr == b.lg)
        if (rez.dr < rez.dr + a.dr)
            rez.dr += a.dr,
            rez.ldr += a.ldr;

    if (sol.st > rez.st) rez.st = sol.st, rez.lst = sol.lst;
    if (sol.dr > rez.dr) rez.dr = sol.dr, rez.ldr = sol.ldr;

    rez.mij = max (max (a.mij, b.mij), sol.mij);
    rez.mij = max (max (rez.st, rez.dr), rez.mij);

    return rez;
}

inline void build ()
{
    for (int i = n - 1; i; --i)
        arb[i] = unite (arb[i << 1], arb[i << 1 | 1]);
}

inline long long querry (int stanga, int dreapta)
{
    aww rst, rdr;
    for (stanga += n - 1, dreapta += n; stanga < dreapta; stanga >>= 1, dreapta >>= 1)
    {
        if (stanga & 1) rst = unite (rst, arb[stanga++]);
        if (dreapta & 1) rdr = unite (arb[--dreapta], rdr);
    }

    return unite (rst, rdr).mij;
}

int main ()
{
    ifstream cin ("sequencequerry.in");
    ofstream cout ("sequencequerry.out");

    cin >> n >> m;

    for (int i = 0; i < n; ++i)
    {
        long long x;
        cin >> x;

        arb[i + n] = aww (x);
    }

    build ();

    for (; m; --m)
    {
        int x, y;
        cin >> x >> y;
        long long rez = querry (x, y);
        if (rez < 0)
        {
            cout << '-';
            rez = -rez;
        }

        cout << rez << '\n';
    }

    return 0;
}