//100p

#include <stdio.h>
#include <string.h>
#include <algorithm>
#define MAX(a, b) ( (a) < (b) ? (b) : (a) )
#define MMAX 300001
#define NMAX 21
#define PMAX 20
#define KMAX 5

using namespace std;

int A[NMAX][NMAX][KMAX + 1];
int S[NMAX][NMAX][KMAX + 1];
int V[MMAX], St[NMAX], U[NMAX];
int i, j, k, N, M;
int K, P, maxs, sum, rest, sm;

void back(int i, int r)
{
	int k, j;
	
	if (i > K - 1)
	{		
		sum = 0;
		memset(U, 0, sizeof(U));
		
		rest = (4 * P - sm) % P, St[K] = rest;
		
		for (j = 1; j <= K; j++) U[St[j]]++;
		
		for (j = 0; j < P; j++) 
			if (U[j] > A[P][j][0]) { sum = -1; break; }
			else                     sum += S[P][j][U[j]];

		maxs = MAX(maxs, sum);
	}
	else
	{
		for (k = r; k < P; k++)
		{
			sm += k, St[i] = k;
			
			back(i + 1, k);
			
			sm -= k, St[i] = -1; 
		}
	}
}

int main()
{
	freopen("tricouri.in", "r", stdin);
	freopen("tricouri.out", "w", stdout);
	
	scanf("%d %d", &N, &M);
	
	for (i = 1; i <= N; i++) scanf("%d", &V[i]);
	
	sort(V + 1, V + N + 1);
	
	for (i = N; i >= 1; i--)
	{
		for (j = 2; j <= PMAX; j++)
				if (A[j][V[i] % j][0] < KMAX)
				{
					k = V[i] % j;
					
					int nr = ++A[j][k][0];
					
					A[j][k][nr] = V[i], S[j][k][nr] = S[j][k][nr - 1] + A[j][k][nr];
				}
	}
	
	for (i = 1; i <= M; i++)
	{		
		maxs = -1, sum = 0, rest = 0, sm = 0;
		
		for (j = 0; j <= KMAX; j++) St[j] = -1;
		
		scanf("%d %d", &K, &P);
		
		back(1, 0);
				
		printf("%d\n", maxs);
	}		
			 
		
	return 0;
	
}