#include<bits/stdc++.h>
using namespace std;
#define int long long

struct Node{
    int ans, _min, _max;
    Node(){ans = -1; _min=1e9; _max=-1e9;}
    Node(int a, int b){
        ans = b;
        _min = a;
        _max = a;
    }
};
vector<Node> tree;
vector<int> s;

Node merge_(Node t1, Node t2){
    if(t1.ans == -1) return t2;
    if(t2.ans == -1) return t1;
    print2(t1);
    print2(t2);
    Node t;
    t.ans = max(t1.ans, max(t2.ans, max(t2._max - t1._min + 1, 0ll) ));
    t._min = min(t1._min, t2._min);
    t._max = max(t1._max, t2._max);
    print2(t);
    return t;
}

Node build(int l, int r, int v){
    if(l == r) return tree[v] = Node(s[l], 1);
    int m = (l + r) / 2;
    return tree[v] = merge_(build(l, m, 2 * v + 1), build(m + 1, r, 2* v + 2));
}

Node find_(int L, int R, int tl, int tr, int v){
    if(tl > R || tr < L) return Node(1, -1);
    if(L <= tl && tr <= R) return tree[v];
    int tm = (tl + tr) / 2;
    return merge_(find_(L, R, tl, tm, 2 * v + 1), find_(L, R, tm + 1, tr, 2 * v + 2));
}

signed main(){
    int n, m;
    cin >> n >> m;
    s.resize(n);
    for(int i = 0; i < n; ++i) cin >> s[i];
    tree.assign(4 * n + 4, Node(1, -1));
    build(0, n - 1, 0);
    int a, b;
    for(int i = 0; i < m; ++i){
        cin >> a >> b;
        --a;--b;
        Node q = find_(a, b, 0, n - 1, 0);
        cout << q.ans << '\n';
    }
    return 0;
}