Game with cards, reward and payment

Random rnd = new Random();

Random rnd = new Random();
int rounds = 1000;
double fullReward = 0;
int payment = 100;
int fullPayment = 0;
Dictionary d = new Dictionary
    {
        [1] = 0.5,
        [2] = 1,
        [3] = 2,
        [4] = 4,
        [5] = 8,
        [6] = 16,
        [7] = 32,
        [8] = 64,
        [9] = 128,
        [10] = 256,
        [11] = 512,
        [12] = 1024,
        [13] = 2048

    };

for(int i = 0; i < rounds; i++){

    int reward = rnd.Next(1,13+1);
    fullReward += d[reward];
    fullPayment += payment;

}

Console.WriteLine(fullReward);
Console.WriteLine(fullPayment);