import java.util.Scanner;

public class Navigation {
    public static void main(String[] args) {
        Scanner userInput = new Scanner(System.in);

        int r = Integer.parseInt(userInput.nextLine());
        int c = Integer.parseInt(userInput.nextLine());
        int n = Integer.parseInt(userInput.nextLine());

        String[] values = userInput.nextLine().split("\\s+");
        double[] codes = new double[n];

        for (int i = 0; i < codes.length; i++) {
            codes[i] = Double.parseDouble(values[i]);
        }
        int[][] matrix = new int[r][c];
        int ro = -1;

        for (int row = r - 1; row >= 0; row--) {
            ro++;
            matrix[row][0] = (int) (Math.pow(2, ro + 1)) / 2;

            int column = 1;
            for (int col = (int) Math.pow(2, row); col <= (Math.pow(2, c - 1)) * ((Math.pow(2, row))) / 2; col *= 2) {
                matrix[ro][column++] = col * 2;
            }
        }

        boolean[][] visited = new boolean[r][c];

        int moves = 1;
        int currentRow = r - 1;
        int currentCol = 0;
        long sum = 0;

        while (moves <= n) {
            for (int i = 0; i < codes.length; i++) {
                int coefficient = Math.max(r, c);
                int row = (int)codes[i] / coefficient;
                int col = (int)codes[i] % coefficient;
                if (row >= r) {
                    row = r - 1;
                }
                if (col >= c) {
                    col = c - 1;
                }
                if(row < 0){
                    row = 0;
                }
                if(col < 0){
                    col = 0;
                }
                if (currentCol < col) {
                    sum = getSumColRight(matrix[currentRow], visited[currentRow], currentCol, sum, col);
                    currentCol = col;
                    if (currentRow > row) {
                        sum = getSumRowUp(matrix, visited, currentRow, currentCol, sum, row);
                    } else if (currentRow < row) {
                        for (int j = currentRow + 1; j <= row; j++) {
                            if (!visited[j][currentCol]) {
                                visited[j][currentCol] = true;
                                sum += matrix[j][currentCol];
                            }
                        }
                    }

                } else if (currentCol > col) {
                    for (int j = currentCol; j > col; j--) {
                        if (!visited[currentRow][j]) {
                            visited[currentRow][j] = true;
                            sum += matrix[currentRow][j];
                        }
                    }
                    currentCol = col;
                    if (currentRow > row) {
                        sum = getSumRowUp(matrix, visited, currentRow, currentCol, sum, row);
                    } else if (currentRow < row) {
                        sum = getSumRowDown(matrix, visited, currentRow, currentCol, sum, row);
                    }

                } else {
                    if (currentRow > row) {
                        sum = getSumRowUp(matrix, visited, currentRow, currentCol, sum, row);
                    } else if (currentRow < row) {
                        sum = getSumRowDown(matrix, visited, currentRow, currentCol, sum, row);
                    }
                }
                currentRow = row;


                moves++;
            }

        }

        System.out.println(sum);
    }

    private static long getSumRowDown(int[][] matrix, boolean[][] visited, int currentRow, int currentCol, long sum, int row) {
        for (int j = currentRow + 1; j <= row; j++) {
            if (!visited[j][currentCol]) {
                visited[j][currentCol] = true;
                sum += matrix[j][currentCol];
            }
        }
        return sum;
    }

    private static long getSumRowUp(int[][] matrix, boolean[][] visited, int currentRow, int currentCol, long sum, int row) {
        for (int j = currentRow - 1; j >= row; j--) {
            if (!visited[j][currentCol]) {
                visited[j][currentCol] = true;
                sum += matrix[j][currentCol];
            }
        }
        return sum;
    }

    private static long getSumColRight(int[] matrix, boolean[] booleans, int currentCol, long sum, int col) {
        for (int j = currentCol; j <= col; j++) {
            if (!booleans[j]) {
                booleans[j] = true;
                sum += matrix[j];
            }
        }
        return sum;
    }


}