#include<bits/stdc++.h>
#include<algorithm>
using namespace std;
int main() {
	long long n;
    cin >> n;
	long long nums[1000010];
	for (int i = 1; i <= n; i++) {
		cin >> nums[i];
		nums[i] = (nums[i] + nums[i - 1]) % 7;
	}
	long long first[1000010]={0}, last[1000010]={0};

	for (int i = n; i>=1; i--){
		first[nums[i]] = i;
	first[0] = 0;
    }
	for (int i = 1; i <= n; i++) {
		last[nums[i]] = i;
	}
	long long ans = -1;
	for (int i = 0; i < 7; i++) {
	ans = max(ans, last[i] - first[i]);
	}

	cout << ans<< endl;

	return 0;
}