# pragma GCC optimize("O3")
# include <bits/stdc++.h>
# define maxn 100001
# define ll long long
# define clock (clock() * 1000.0 / CLOCKS_PER_SEC)
# define rc(s) return cout << s,0
# define _ ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
# define pb push_back
# define mp make_pair
//# define int ll
using namespace std;
const int inf = INT_MAX;

inline int readChar();
template <class T = int> inline T readInt();
template <class T> inline void writeInt( T x, char end = 0 );
inline void writeChar( int x );
inline void writeWord( const char *s );

/** Read */

static const int buf_size = 4096;

inline int getChar() {
    static char buf[buf_size];
    static int len = 0, pos = 0;
    if (pos == len)
        pos = 0, len = fread(buf, 1, buf_size, stdin);
    if (pos == len)
        return -1;
    return buf[pos++];
}

inline int readChar() {
    int c = getChar();
    while (c <= 32)
        c = getChar();
    return c;
}

template <class T>
inline T readInt() {
    int s = 1, c = readChar();
    T x = 0;
    if (c == '-')
        s = -1, c = getChar();
    while ('0' <= c && c <= '9')
        x = x * 10 + c - '0', c = getChar();
    return s == 1 ? x : -x;
}

inline ll readLong() {
    int s = 1, c = readChar();
    ll x = 0;
    if (c == '-')
        s = -1, c = getChar();
    while ('0' <= c && c <= '9')
        x = x * 10 + c - '0', c = getChar();
    return s == 1 ? x : -x;
}

/** Write */

static int write_pos = 0;
static char write_buf[buf_size];

inline void writeChar( int x ) {
    if (write_pos == buf_size)
        fwrite(write_buf, 1, buf_size, stdout), write_pos = 0;
    write_buf[write_pos++] = x;
}

template <class T>
inline void writeInt( T x, char end ) {
    if (x < 0)
        writeChar('-'), x = -x;

    char s[24];
    int n = 0;
    while (x || !n)
        s[n++] = '0' + x % 10, x /= 10;
    while (n--)
        writeChar(s[n]);
    if (end)
        writeChar(end);
}

inline void writeWord( const char *s ) {
    while (*s)
        writeChar(*s++);
}

struct Flusher {
    ~Flusher() {
        if (write_pos)
            fwrite(write_buf, 1, write_pos, stdout), write_pos = 0;
    }
} flusher;


int a[maxn];
int n,m,l,r;

struct data
{
	ll sum;
    ll best;
    ll lbest;
    ll rbest;
}t[4 * maxn];

inline data combo(data a,data b)
{
    data tmp;
    tmp.sum = a.sum + b.sum;
    tmp.lbest = max({tmp.sum,a.lbest,a.sum + b.lbest});
    tmp.rbest = max({tmp.sum,b.rbest,b.sum + a.rbest});
    tmp.best = max({tmp.lbest,tmp.rbest,a.rbest+b.lbest,tmp.sum,a.best,b.best});
    return tmp;
};

inline void build(int nod,int l,int r)
{
	if(l == r)
	{
		t[nod] = {a[l],a[l],a[l],a[l]};
		return ;
	}
    int mid = l + r >> 1;
    build(nod << 1,l,mid);
    build(nod << 1 | 1,mid + 1,r);
    t[nod] = combo(t[nod << 1],t[nod << 1 | 1]);
}

inline data qry(int nod,int tl,int tr,int l,int r)
{
	if(l > r) return {-inf,-inf,-inf,-inf};
    if(l == tl && r == tr) return t[nod];
    int mid = tl + tr >> 1;
    return combo(qry(nod << 1,tl,mid,l,min(mid,r)),qry(nod << 1 | 1,mid + 1,tr,max(mid + 1,l),r));
}

int32_t main(){_
    freopen("sequencequery.in","r",stdin);
    freopen("sequencequery.out","w",stdout);
	n = readInt();
	m = readInt();
    for(int i = 1;i<=n;i++)
		a[i] = readInt();
	build(1,1,n);
	while(m --)
	{
		l = readInt();
		r = readInt();
		writeInt(qry(1,1,n,l,r).best,'\n');
	}
	return 0;
}