#include <iostream>
#include <iomanip>
#include<iterator> // for iterators
#include<vector> // for vectors
#include <utility>
#include <algorithm>
#include <set>
#include <map>
#include <stack>
#include <unordered_map>
using namespace std;

int main()
{
    ios_base :: sync_with_stdio (false);
    cin.tie (NULL);
    cout.tie (NULL);
    int n; scanf("%d", &n);
    vector<int> v;
    for (int i = 0; i < n; ++i) {
        int temp;
        scanf("%d", &temp);
        v.emplace_back(temp);
    }
    int max = 0, temp;
    for (int i = 0; i < n; ++i)
    {
        for (int j = i; j < n; ++j)
        {
            if (v[i] == v[j])
                temp = j - i;
            if (temp > max)
                max = temp;
        }
    }
    printf("%d\n", max+1);
    return 0;
}