#include <bits/stdc++.h>
#ifndef LOCAL
#include "meetings.h"
#endif
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define Time (clock() * 1.0 / CLOCKS_PER_SEC)
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1& x, T2 y) {
return y < x ? (x = y, true) : false;
}
template<typename T1, typename T2> bool chkmax(T1& x, T2 y) {
return y > x ? (x = y, true) : false;
}
void debug_out() {
cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
cerr << ' ' << A;
debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
for (int i = 0; i < n; ++i)
cerr << a[i] << ' ';
cerr << endl;
}
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
#define debug(...) 1337
#define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T>& v) {
for (auto& x : v)
stream << x << ' ';
return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
return stream << p.first << ' ' << p.second;
}
template<typename T> ostream& operator << (ostream& stream, const deque<T>& v) {
for (auto& x : v)
stream << x << ' ';
return stream;
}
const int INF32 = 1e9;
const ll INF64 = 1e18;
const int maxN = 150005;
int n, Q;
int a[maxN];
vector<int> que[maxN];
namespace sgt {
const int logN = 20;
const int N = 1 << logN;
int t[2 * N];
void build() {
for (int i = 0; i < n; ++i)
t[i + N] = i;
for (int i = N - 1; i >= 1; --i) {
if (a[t[i << 1]] > a[t[i << 1 | 1]])
t[i] = t[i << 1];
else
t[i] = t[i << 1 | 1];
}
}
int argmax(int l, int r) {
int i = l;
for (l += N, r += N; l <= r; l >>= 1, r >>= 1) {
if (l & 1) {
if (mp(a[t[l]], t[l]) > mp(a[i], i))
i = t[l];
++l;
}
if (~r & 1) {
if (mp(a[t[r]], t[r]) > mp(a[i], i))
i = t[r];
--r;
}
}
return i;
}
}
struct line {
ll k, b;
line() {}
line(ll _k, ll _b): k(_k), b(_b) {}
ll f(ll x) {
return k * x + b;
}
};
ostream& operator << (ostream& stream, const line& l) {
return stream << l.k << "i + " << l.b;
}
double intersect(const line& lhs, const line& rhs) {
return (rhs.b - lhs.b) / (double)(lhs.k - rhs.k);
}
struct DS {
ll delta;
deque<line> val;
deque<int> L;
int R;
DS() {}
DS(ll x, int l) {
delta = 0;
val = {{0, x}};
L = {l};
}
void clear() {
delta = 0;
val.clear();
L.clear();
}
int size() {
return val.size();
}
void pushBack(int i, ll x) {
x -= delta;
val.push_back({0, x});
L.push_back(i);
}
void pushFront(int i, ll x) {
x -= delta;
val.push_front({0, x});
L.push_front(i);
}
void add(ll d) {
delta += d;
}
void relaxPrefix(line e) {
if (val.empty()) return;
if (val[0].f(L[0]) <= e.f(L[0])) return;
e.b -= delta;
int l = L[0];
while (!val.empty() && val[0].f(L[0]) > e.f(L[0])) {
int r = (val.size() > 1 ? L[1] - 1 : R);
if (val[0].f(r) >= e.f(r)) {
val.pop_front();
L.pop_front();
} else {
L[0] = ceil(intersect(e, val[0]));
break;
}
}
val.push_front(e);
L.push_front(l);
}
ll f(int i) {
// if (val.empty()) return 0;
int t = upper_bound(all(L), i) - L.begin() - 1;
if (t < 0) return 0;
return val[t].f(i) + delta;
}
} PP[maxN];
vector<ll> minimum_costs(vector<int> _a, vector<int> ql, vector<int> qr) {
n = _a.size(), Q = ql.size();
for (int i = 0; i < n; ++i)
a[i] = _a[i];
vector<ll> ans(Q, INF64);
for (int rot = 0; rot < 2; ++rot) {
for (int i = 0; i < n; ++i) {
que[i].clear();
PP[i].clear();
}
sgt::build();
for (int i = 0; i < Q; ++i) {
int j = sgt::argmax(ql[i], qr[i]);
que[j].push_back(i);
}
function<int(int, int)> solve = [&](int L, int R) {
if (L > R) return n + 1;
int I = sgt::argmax(L, R);
ll M = a[I];
// debug(L, R);
auto& P = PP[I];
int IL = solve(L, I - 1);
auto& PL = PP[IL];
int IR = solve(I + 1, R);
auto& PR = PP[IR];
for (int q : que[I]) {
int l = ql[q], r = qr[q];
chkmin(ans[q], PR.f(r) + M * (I - l + 1));
}
PR.add(M * (I - L + 1));
PR.relaxPrefix({M, PL.f(I - 1) - M * (I - 1)});
if (PR.size() <= PL.size()) {
swap(P, PL);
P.R = R;
P.pushBack(I, P.f(I - 1) + M);
for (int i = I + 1, t = 0; i <= R; ++i) {
while (t + 1 < PR.size() && PR.L[t + 1] <= i)
++t;
P.pushBack(i, PR.f(i) + PR.delta);
}
} else {
swap(P, PR);
P.R = R;
P.pushFront(I, PL.f(I - 1) + M);
for (int i = I - 1, t = PL.size() - 1; i >= L; --i) {
while (PL.L[t] > i)
--t;
P.pushFront(i, PL.f(i) + PL.delta);
}
}
// debug(L, I, R);
// debug(P.val);
// debug(P.L);
// for (int i = L; i <= R; ++i)
// cerr << P.f(i) << ' ';
// cerr << endl;
return I;
};
solve(0, n - 1);
reverse(a, a + n);
for (int i = 0; i < Q; ++i) {
ql[i] = n - ql[i] - 1;
qr[i] = n - qr[i] - 1;
swap(ql[i], qr[i]);
}
}
return ans;
}
#ifdef LOCAL
int read_int() {
int x;
if (scanf("%d", &x) != 1) {
fprintf(stderr, "Error while reading input\n");
exit(1);
}
return x;
}
int32_t main() {
#ifdef LOCAL
freopen("in", "r", stdin);
#endif
ios::sync_with_stdio(0);
cin.tie(0);
int N = read_int();
int Q = read_int();
std::vector<int> H(N);
for (int i = 0; i < N; ++i) {
H[i] = read_int();
}
std::vector<int> L(Q), R(Q);
for (int j = 0; j < Q; ++j) {
L[j] = read_int();
R[j] = read_int();
}
std::vector<long long> C = minimum_costs(H, L, R);
for (size_t j = 0; j < C.size(); ++j) {
printf("%lld\n", C[j]);
}
return 0;
return 0;
}
#endif
