#include <cstdint>
#include <iostream>
static const std::size_t MAX_N = 500000;
static std::uint_fast64_t growth[MAX_N];
static std::uint_fast64_t current[MAX_N];
int main()
{
std::uint_fast32_t n, m;
std::cin >> n >> m;
for (decltype(n) i = 0; i < n; ++i)
std::cin >> growth[i];
std::uint_fast64_t previous_day = 0;
for (decltype(m) i = 0; i < m; ++i)
{
std::uint_fast64_t day, length;
std::cin >> day >> length;
std::uint_fast64_t sum = 0;
for (decltype(n) j = 0; j < n; ++j)
{
std::uint_fast64_t updated = current[j] + growth[j] * (day - previous_day);
if (updated > length)
{
sum += updated - length;
current[j] = length;
}
else
current[j] = updated;
}
std::cout << sum << std::endl;
previous_day = day;
}
}