import java.util.*;
 
public class Main{
  public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int cnt=n;
        int prev = 0;
        for(int i=0; i<n; i++){
            String s = sc.next();
            boolean[] arr = new boolean[26];
            for(int j=0; j<s.length(); j++){
                if(prev != s.charAt(j)){
                    if(arr[s.charAt(j) - 'a'] == false){
                        arr[s.charAt(j) - 'a'] = true;
                        prev = s.charAt(j);
                    }else{
                        cnt--;
                        break;
                    }
                }
 
            }
        }
        System.out.print(cnt);
    }
}

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

MgphCmFiYQo=

2
a
aba