import java.util.*;
import java.lang.*;
import java.io.*;

public class Main {
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		// 入力
		FastScanner sc = new FastScanner(System.in);
		int N = sc.nextInt();
		int[] A = new int[N];
		for(int i = 0; i < N; i++){
			A[i] = sc.nextInt();
		}
		
		// dp表作成
		int[][] dp = new int[N+10][10];
		for(int i = 0; i < N+10; i++){
			for(int j = 0; j < 10; j++){
				dp[i][j] = -1000000;
			}
		}
		dp[0][0] = 0;
		for(int i = 0; i < N; i++){
			for(int j = 0; j < 10; j++){
				int amari = A[i] % 10;
				int target = 0;
				if(j >= amari){
					target = j - amari;
				}else{
					target = j + 10 - amari;
				}
				dp[i+1][j] = chmax(dp[i][j], dp[i][target] + 1);
			}
		}
		
		// 出力
		System.out.println(dp[N][0]);
	}
	
	// 2数のうち、大きい数を返す関数
	public static int chmax(int a, int b){
		if(a < b){
			return b;
		}
		return a;
	}

	// 高速スキャナー
    static class FastScanner {
        private BufferedReader reader = null;
        private StringTokenizer tokenizer = null;

        public FastScanner(InputStream in) {
            reader = new BufferedReader(new InputStreamReader(in));
            tokenizer = null;
        }

        public String next() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public String nextLine() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    return reader.readLine();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }

            return tokenizer.nextToken("\n");
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public double nextDouble() {
             return Double.parseDouble(next());
         }

        public int[] nextIntArray(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }

        public long[] nextLongArray(int n) {
            long[] a = new long[n];
            for (int i = 0; i < n; i++)
                a[i] = nextLong();
            return a;
        } 
    }
}