import java.util.*;
class TestClass {
    public static void main(String args[] ) throws Exception {
        /*
         * Read input from stdin and provide input before running
         * Use either of these methods for input

        //BufferedReader
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line = br.readLine();
        int N = Integer.parseInt(line);

        //Scanner
        Scanner s = new Scanner(System.in);
        int N = s.nextInt();

        for (int i = 0; i < N; i++) {
            System.out.println("hello world");
        }
        */

        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();
        int count = 0;
        String s;
        int length;
        char ch;


        for(int i = 0; i < t; i++){
            length = sc.nextInt();
            s = sc.nextLine();


            for(int j = 0; j < length; j++){
                ch = s.charAt(j);
                if(ch >= '0' && ch <= '9'){


                    //do{
                        //j++;
                    //}while(ch >= '0' && ch <= '9');
                    do{


                        j++;
                    }while(ch >= '0' && ch <= '9');
                    count++;
                }





            }
            //System.out.println(count);
            //count = 0;
        }

        System.out.println(count);

    }








}