#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <unordered_map>
#include <limits.h>
using namespace std;
int main()
{
int n, k;
cin >> n;
vector<int> v(n);
for (auto i = 0; i != n; ++i)
cin >> v[i];
cin >> k;
unordered_map<int, int> dict;
dict.insert(make_pair(0, -1));
int sum = 0;
int res = INT_MIN;
for (auto i = 0; i != n; ++i)
{
sum += v[i];
if (dict.find(sum) == dict.end()) dict.insert(make_pair(sum%k, i));
int temp = sum%k;
if (dict.find(temp) != dict.end())
res = max(res, i - dict[temp]);
}
cout << res << endl;
return 0;
}