package left_recursion;

import java.util.*;

import java.io.*;

public class LeftRecursion {

private static ArrayList<String> data = new ArrayList<>();

private static ArrayList<String> dataLine = new ArrayList<>();

private static void getData() throws IOException{ // Получение данных

FileReader file = new FileReader("input.txt");

Scanner sc = new Scanner(file);

while (sc.hasNextLine()){

dataLine.add(sc.nextLine());

}

for(int i = 0; i < dataLine.size(); i++){

if(i != 0){

StringTokenizer st = new StringTokenizer(dataLine.get(i), "->");

while (st.hasMoreTokens()){

data.add(st.nextToken());

}

}

}

}

public static void main(String[] argv) throws IOException{

getData();

int count = 0;

String left = "";

for(int i = 0; i < data.size(); i++){

if(i % 2 == 0){

left = data.get(i);

}else{

char oneSymbolRight = data.get(i).charAt(0);

if(left.equals(String.valueOf(oneSymbolRight))){

count++;

}

}

}

PrintWriter pw = new PrintWriter(new File("output.txt"));

pw.print(String.valueOf(count));

pw.close();

}

}