import java.util.*;

public class Main {

    public static int solution(int[] arr, int k) {
//make hashmap<PSA,Index> and keep storing PSA , if (PSA - k) exists and is divisible by k store length of i - index of (psa-k)


        
        HashMap<Integer, Integer> map = new HashMap<>();
        int psa = 0 , ans = 0 ;
        map.put(0 , -1);
        
        for(int i =0 ;i < arr.length ; i++){
            int val = arr[i];
            psa += val;
            
            //find remainder
            int rem = psa%k;
            
            //if remainder comes out to be -ve add k
            if(rem < 0) rem += k;
            
            if(map.containsKey(rem))
                ans = Math.max(ans , i - map.get(rem));
            
            else
                map.put(rem , i);
            
        }

        return ans;
    }
    
    public static void main(String[] args) {
        Scanner scn = new Scanner(System.in);
        int n = scn.nextInt();
        int[] arr = new int[n];
        for (int i = 0; i < n; i++) {
            arr[i] = scn.nextInt();
        }
        int k = scn.nextInt();
        System.out.println(solution(arr, k));
    }

}