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#include <iostream>
#include <string>
#include <cctype>

#define SIZE_OF_ARRAY(x) (sizeof(x) / sizeof(*(x)))

#ifndef _MSC_VER
#define __int64 long long
#endif

typedef unsigned int uint;
typedef unsigned __int64 uint64;

static char get_char_buffer[4 * 1024];
static std::size_t get_char_buffer_i = SIZE_OF_ARRAY(get_char_buffer);
static std::size_t get_char_buffer_n = SIZE_OF_ARRAY(get_char_buffer);

static char get_char_prefix = 0;
static char get_char_result = 0;

int get_char()
{
	get_char_result = 0;

	if (get_char_prefix)
	{
		get_char_result = get_char_prefix;

		get_char_prefix = 0;
	}
	else if (get_char_buffer_n == 0)
	{
		get_char_result = std::char_traits<char>::eof();
	}
	else if (get_char_buffer_i < get_char_buffer_n)
	{
		get_char_result = get_char_buffer[get_char_buffer_i++];
	}
	else
	{
		std::cin.read(get_char_buffer, SIZE_OF_ARRAY(get_char_buffer));

		get_char_buffer_i = 0;
		get_char_buffer_n = std::cin.gcount();

		return get_char();
	}

	return get_char_result;
}

void unget_char()
{
	get_char_prefix = get_char_result;
}

uint get_uint()
{
	int c;
	while (isspace(c = get_char()));

	uint value = (c - '0');

	while (isdigit(c = get_char()))
	{
		value = (10 * value) + (c - '0');
	}

	return value;
}

uint64 get_uint64()
{
	int c;
	while (isspace(c = get_char()));

	uint64 value = (c - '0');

	while (isdigit(c = get_char()))
	{
		value = (10 * value) + (c - '0');
	}

	return value;
}

static char put_uint_buffer[16];

void put_uint(uint value)
{
	if (value == 0)
	{
		std::cout.put('0');

		return;
	}

	int i;
	for (i = SIZE_OF_ARRAY(put_uint_buffer); value != 0; value /= 10)
	{
		put_uint_buffer[--i] = '0' + (value % 10);
	}

	std::cout.write(put_uint_buffer + i, SIZE_OF_ARRAY(put_uint_buffer) - i);
}

static char put_uint64_buffer[32];

void put_uint64(uint64 value)
{
	if (value == 0)
	{
		std::cout.put('0');

		return;
	}

	int i;
	for (i = SIZE_OF_ARRAY(put_uint64_buffer); value != 0; value /= 10)
	{
		put_uint64_buffer[--i] = '0' + (value % 10);
	}

	std::cout.write(put_uint64_buffer + i, SIZE_OF_ARRAY(put_uint64_buffer) - i);
}

uint a[500005];
uint64 grass[500005];

int main()
{
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(0);

	uint n = get_uint();
	uint m = get_uint();

	for (uint i = 0; i < n; ++i)
	{
		a[i] = get_uint();
	}

	uint64 last_d = 0;

	for (uint j = 0; j < m; ++j)
	{
		uint64 d = get_uint64();
		uint64 b = get_uint64();

		uint64 days = d - last_d;

		uint64 result = 0;

		for (uint i = 0; i < n; ++i)
		{
			grass[i] += days * a[i];

			if (grass[i] >= b)
			{
				result += (grass[i] - b);

				grass[i] = b;
			}
		}

		put_uint64(result); std::cout.put('\n');

		last_d = d;
	}

	return 0;
}