import java.util.*;
public class Main{
public static void main(String[] arg){
Scanner sc = new Scanner(System.in);
int sum=0;
for(int i=1;i<=5;i++){
String year = sc.next();
if(year.charAt(0)==year.charAt(2)&&(year.charAt(3)-year.charAt(1))==1){
sum+=1;
}
}
System.out.println(sum);
}
}