import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

class DayThree {
    public static void main(String[] args) {
        int treeCount = 0;
        int xLoc = 0;
        int yLoc = 0;
        int maxRows = 1;
        int xStep = 1;
        int yStep = 2;
        int[] rowTreeIndex;
        int[][] trees;
        int indexCounter = 0;
        trees = new int[400][31];
        try {
            File inputFile = new File("input.txt");
            Scanner readFile = new Scanner(inputFile);
            while (readFile.hasNextLine()) {
                String inputLine = readFile.nextLine();
                rowTreeIndex = findTrees(inputLine);
                for (int i = 0; i < rowTreeIndex.length; i++) {
                    trees[indexCounter][i] = rowTreeIndex[i];
                    // System.out.println(trees[indexCounter][i]);
                }
                indexCounter++;
                maxRows++;
            }
            // System.out.println(maxRows);
            readFile.close();
        } catch (FileNotFoundException e) {
            System.out.println("crapeth");
        }

        while (yLoc != maxRows) {
            // System.out.println(xLoc % 31);
            if (hitTree(trees[yLoc], xLoc % 31, yLoc)) {
                treeCount++;
            }
            xLoc = xStep + xLoc;
            yLoc = yStep + yLoc;
        }
        System.out.println(treeCount);
    }

    public static int[] findTrees(String inputString) {
        int indexCount = 0;
        int[] treeIndex;
        char[] stringToChar;
        treeIndex = fill();
        stringToChar = inputString.toCharArray();
        for (int i = 0; i < inputString.length(); i++) {
            // System.out.println(stringToChar[i]);
            if (stringToChar[i] == '#') {
                treeIndex[indexCount] = i;
                indexCount++;
            }
        }
        return treeIndex;
    }

    public static boolean hitTree(int[] inputArray, int inputX, int inputY) {
        boolean treeHit = false;
        // System.out.println(inputY);
        // System.out.print(" ");
        for (int i = 0; i < inputArray.length; i++) {
            // System.out.print(inputArray[i]);
            // System.out.print(" ");
        }

        System.out.println();
        for (int i = 0; i < inputArray.length; i++) {
            if (inputX == inputArray[i]) {
                treeHit = true;
            }
        }

        return treeHit;
    }

    public static int[] fill() {
        int[] whale;
        whale = new int[31];
        for (int i = 0; i < 31; i++) {
            whale[i] = 40;
        }
        return whale;

    }
}