import java.util.*;

public class Main {
	public static void main (String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int n = sc.nextInt();
    	boolean[][] exists = new boolean[n + 1][10];
    	exists[0][0] = true;
    	int max = 0;
    	for (int i = 1; i <= n; i++) {
    	    int x = sc.nextInt() % 10;
    	    for (int j = i - 1; j >= 0 && j + 1 + (n - i + 1) > max; j--) {
    	        for (int k = 0; k < 10; k++) {
    	            if (exists[j][k]) {
    	                exists[j + 1][(k + x) % 10] = true;
    	            }
    	        }
    	        if (exists[j + 1][0]) {
    	            max = Math.max(max, j + 1);
    	        }
    	    }
    	}
    	System.out.println(max);
	}
}