import java.math.BigInteger;
import java.util.Arrays;
import java.util.Scanner;


//Tazi zadacha me poburka


public class Main {
    public static final Scanner sc = new Scanner(System.in);

    public static BigInteger[][] fulfillMatrix(BigInteger[][] matrix) {


        int row = matrix.length;
        int col = matrix[0].length;
        BigInteger num = BigInteger.valueOf(1);
        for (int i = row - 1; i >= 0; i--) {
            for (int j = 0; j < col; j++) {
                matrix[i][j] = num;
                num =num.multiply(BigInteger.valueOf(2));
            }
            num = matrix[i][1];
        }
        return matrix;

    }


    public static void main(String[] args) {
        int row = sc.nextInt();
        int col = sc.nextInt();
        long sum = 0;
        BigInteger sum1=BigInteger.valueOf(0);

        int max = Math.max(row, col);

        boolean[][] matrixCheck = new boolean[row][col];
        BigInteger[][] matrixNumbers = new BigInteger[row][col];

        fulfillMatrix(matrixNumbers);




        int number = sc.nextInt();
        int[] arr = new int[number];
        for (int i = 0; i < number; i++) {
            arr[i] = sc.nextInt();
        }


        int currentRow = row - 1;
        int currentCol = 0;

        for (int i = 0; i < number; i++) {
            row = arr[i] / max;
            col = arr[i] % max;


            if (col > currentCol && row == currentRow) {
                for (int j = currentCol; j <= col; j++) {
                    if (!matrixCheck[currentRow][j]) {

                        sum1=sum1.add(matrixNumbers[currentRow][j]);
                        matrixCheck[currentRow][j] = true;
                    }
                }
                currentRow = row;
                currentCol = col;
                continue;

            }

            if (col < currentCol && row == currentRow) {
                for (int j = currentCol; j >= col; j--) {
                    if (!matrixCheck[currentRow][j]) {

                        sum1=sum1.add(matrixNumbers[currentRow][j]);
                        matrixCheck[currentRow][j] = true;
                    }
                }
                currentRow = row;
                currentCol = col;
                continue;
            }


            if (col == currentCol && row > currentRow) {
                for (int j = currentRow; j <= row; j++) {
                    if (!matrixCheck[j][currentCol]) {

                        sum1=sum1.add(matrixNumbers[j][currentCol]);
                        matrixCheck[j][currentCol] = true;
                    }
                }
                currentRow = row;
                currentCol = col;
                continue;
            }



            if (col == currentCol && row < currentRow) {
                for (int j = currentRow; j >= row; j--) {
                    if (!matrixCheck[j][currentCol]) {

                        sum1=sum1.add(matrixNumbers[j][currentCol]);
                        matrixCheck[j][currentCol] = true;
                    }
                }
                currentRow = row;
                currentCol = col;
                continue;
            }

                //row++
                for (int j = currentCol; j <= col; j++) {
                    if (!matrixCheck[currentRow][j]) {

                        sum1=sum1.add(matrixNumbers[currentRow][j]);
                        matrixCheck[currentRow][j] = true;
                    }
                }
                //row--
                for (int j = currentCol; j >= col; j--) {
                    if (!matrixCheck[currentRow][j]) {

                        sum1=sum1.add(matrixNumbers[currentRow][j]);
                        matrixCheck[currentRow][j] = true;
                    }
                }
            currentCol = col;
                //col-
                for (int j = currentRow; j >= row; j--) {
                    if (!matrixCheck[j][currentCol]) {

                        sum1=sum1.add(matrixNumbers[j][currentCol]);
                        matrixCheck[j][currentCol] = true;
                    }
                }
                //col+
                for (int j = currentRow; j <= row; j++) {
                    if (!matrixCheck[j][currentCol]) {

                        sum1=sum1.add(matrixNumbers[j][currentCol]);
                        matrixCheck[j][currentCol] = true;
                    }
                }




            currentRow = row;

        }

        System.out.println(sum1);


    }
}