#include <fstream>
#include <algorithm>

using namespace std;

class InParser {
private:
    FILE *fin;
    char *buff;
    int sp;

    char read_ch() {
        ++sp;
        if (sp == 4096) {
            sp = 0;
            fread(buff, 1, 4096, fin);
        }
        return buff[sp];
    }

public:
    InParser(const char* nume) {
        fin = fopen(nume, "r");
        buff = new char[4096]();
        sp = 4095;
    }

    InParser& operator >> (int &n) {
        char c;
        while (!isdigit(c = read_ch()) && c != '-');
        int sgn = 1;
        if (c == '-') {
            n = 0;
            sgn = -1;
        } else {
            n = c - '0';
        }
        while (isdigit(c = read_ch())) {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }

    InParser& operator >> (long long &n) {
        char c;
        n = 0;
        while (!isdigit(c = read_ch()) && c != '-');
        long long sgn = 1;
        if (c == '-') {
            n = 0;
            sgn = -1;
        } else {
            n = c - '0';
        }
        while (isdigit(c = read_ch())) {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }
};

class OutParser {
private:
    FILE *fout;
    char *buff;
    int sp;

    void write_ch(char ch) {
        if (sp == 50000) {
            fwrite(buff, 1, 50000, fout);
            sp = 0;
            buff[sp++] = ch;
        } else {
            buff[sp++] = ch;
        }
    }


public:
    OutParser(const char* name) {
        fout = fopen(name, "w");
        buff = new char[50000]();
        sp = 0;
    }
    ~OutParser() {
        fwrite(buff, 1, sp, fout);
        fclose(fout);
    }

    OutParser& operator << (int vu32) {
        if (vu32 <= 9) {
            write_ch(vu32 + '0');
        } else {
            (*this) << (vu32 / 10);
            write_ch(vu32 % 10 + '0');
        }
        return *this;
    }

    OutParser& operator << (long long vu64) {
        if (vu64 <= 9) {
            write_ch(vu64 + '0');
        } else {
            (*this) << (vu64 / 10);
            write_ch(vu64 % 10 + '0');
        }
        return *this;
    }

    OutParser& operator << (char ch) {
        write_ch(ch);
        return *this;
    }
    OutParser& operator << (const char *ch) {
        while (*ch) {
            write_ch(*ch);
            ++ch;
        }
        return *this;
    }
};

struct aww
{
    long long st, dr, mij, sum;

    aww ()
    {
        st = dr = mij = -20000000000000000LL;
        sum = 0LL;
    }

    aww (long long x)
    {
        st = dr = mij = sum = x;
    }

} arb[200010];

int n, m;

inline aww unite (aww a, aww b)
{
    aww rez;
    rez.sum = a.sum + b.sum;

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

    return rez;
}

inline void build ()
{
    for (int i = 32 - 1; i; --i)
        arb[i] = unite (arb[i << 1], arb[i << 1 | 1]);
}

inline long long querry (int st, int dr)
{
    aww rst, rdr;
    for (st += 32 - 1, dr += 32; st < dr; st >>= 1, dr >>= 1)
    {
        if (st & 1) rst = unite (rst, arb[st++]);
        if (dr & 1) rdr = unite (arb[--dr], rdr);
    }

    return unite (rst, rdr).mij;
}

int main ()
{
    InParser cin ("sequencequery.in");
    OutParser cout ("sequencequery.out");

    cin >> n >> m;

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

        arb[i + 32] = 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;
}