Problem:
Score : 400 points

Problem Statement

We have N integers. The i-th integer is A_i.

Find \sum_{i=1}^{N-1}\sum_{j=i+1}^{N} (A_i \mbox{ XOR } A_j), modulo (10^9+7).

What is \mbox{ XOR }?

The XOR of integers A and B, A \mbox{ XOR } B, is defined as follows:

When A \mbox{ XOR } B is written in base two, the digit in the 2^k's place (k \geq 0) is 1 if either A or B, but not both, has 1 in the 2^k's place, and 0 otherwise.

For example, 3 \mbox{ XOR } 5 = 6. (In base two: 011 \mbox{ XOR } 101 = 110.)

Constraints

2 \leq N \leq 3 \times 10^5

0 \leq A_i < 2^{60}

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N

Output

Print the value \sum_{i=1}^{N-1}\sum_{j=i+1}^{N} (A_i \mbox{ XOR } A_j), modulo (10^9+7).

Sample Input 1

3
1 2 3

Sample Output 1

6

We have (1\mbox{ XOR } 2)+(1\mbox{ XOR } 3)+(2\mbox{ XOR } 3)=3+2+1=6.

Sample Input 2

10
3 1 4 1 5 9 2 6 5 3

Sample Output 2

237

Sample Input 3

10
3 14 159 2653 58979 323846 2643383 27950288 419716939 9375105820

Sample Output 3

103715602

Print the sum modulo (10^9+7).

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.Linq;
using System.Collections.Generic;

using SyrupBeans.Competitive.Integer;

using E = System.Linq.Enumerable;

public class Program
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine());
        var seqA = Console.ReadLine().Split().Select(x => long.Parse(x)).ToArray();

        var sum = new long[seqA.Length + 1][];
        sum[0] = new long[64];
        for (int i = 1; i < sum.Length; ++i)
        {
            sum[i] = new long[sum[i - 1].Length];
            Array.Copy(sum[i - 1], sum[i], sum[i].Length);

            var a = seqA[i - 1];
            for (int j = 0; j < sum[i].Length; ++j)
            {
                if (a < 1)
                {
                    break;
                }
                sum[i][j] += a & 1;
                a >>= 1;
            }
        }

        var k = new Modular(0, (long)1e9 + 7);
        for (int i = 1; i < seqA.Length; ++i)
        {
            var a = seqA[i - 1];
            for (int j = 0; j < sum[i + 1].Length; ++j)
            {
                var l = seqA.Length - i;
                var one = sum.Last()[j] - sum[i][j];
                k += (l * (a & 1) - one) * (1 - 2 * (~a & 1)) << j;
                a >>= 1;
            }
        }

        Console.WriteLine(k.Remainder);
    }
}

namespace SyrupBeans.Competitive.Integer
{
    using Integer = System.Int64;

    using System;

    public static class Divisibility
    {
        /// <summary>O(log min(<paramref name="x" />, <paramref name="y" />))</summary>
        public static Integer FindGcd(Integer x, Integer y) => x < 1 ? y : FindGcd(y % x, x);
    }

    public struct Modular
    {
        public Integer Modulus { get; private set; }
        public Integer Remainder { get; private set; }

        public Modular(Integer natural, Integer modulus)
        {
            Remainder = natural < modulus ? natural : natural % modulus;
            Modulus = modulus;
        }
        public Modular(Integer natural)
        {
            Remainder = 0;
            Modulus = natural;
        }

        /// <summary>O(log min(<paramref name="a" />, <paramref name="b" />))</summary>
        /// <returns>Satisfying values with the equation: <paramref name="a" />X + <paramref name="b" />Y = Gcd .</returns>
        public static Tuple<Integer, Integer, Integer> FindBézoutIdentity(Integer a, Integer b)
        {
            Integer x = 1, y = 0;
            Integer u = 0, v = 1;
            while (b > 0)
            {
                var k = a / b;
                a = b;
                b = a - k * b;
                x = u; u = 1 * x - k * u;
                y = v; v = 1 * y - k * v;
            }
            return Tuple.Create(x, y, a);
        }

        public Modular AdditiveInversion => new Modular(Modulus - Remainder, Modulus);
        public Modular? MultiplicativeInverse {
            get
            {
                var t = FindBézoutIdentity(this.Remainder, this.Modulus);
                return t.Item3 > 1 ? (Modular?)null : new Modular(t.Item1, this.Modulus);
            }
        }

        public Modular AddWith(Integer x) => new Modular(Remainder + x, Modulus);
        public Modular SubtractWith(Integer x) => new Modular(Remainder - x + Modulus, Modulus);
        public Modular MultiplyWith(Integer x) => new Modular(Remainder * x, Modulus);
        public Modular DivideWith(Integer x) => new Modular(Remainder / x, Modulus / Divisibility.FindGcd(Modulus, x));
        public Modular PowerWith(Integer x) => new Modular((Integer)System.Numerics.BigInteger.ModPow(Remainder, x, Modulus), Modulus);

        public static Modular operator +(Modular x, Integer y) => x.AddWith(y);
        public static Modular operator -(Modular x, Integer y) => x.SubtractWith(y);
        public static Modular operator *(Modular x, Integer y) => x.MultiplyWith(y);
        public static Modular operator /(Modular x, Integer y) => x.DivideWith(y);
        public static Modular Pow(Modular x, Integer y) => x.PowerWith(y);
    }
}