/*
    # Enjoy the journey #
*/
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define pb push_back
#define forq(i , a , b) for (int i = (a); i <= (b); ++i)
#define qrof(i , b , a) for (int i = (a); i >= (b); --i)
#define forr(i , b) forq( i , 0 , b - 1 )
#define F first
#define S second
#define IF ->first
#define IS ->second
#define endl '\n'
#define qqmemset(array , val) memset (array , val , sizeof(array))
#define ALLV(vect) vect.begin() , vect.end()
#define mid (st + en) / 2
#define mid1 (2 * st + en) / 3
#define mid2 (2 * en + st) / 3
#define lef 2 * Node
#define rig lef + 1
mt19937 rng( chrono::steady_clock::now().time_since_epoch().count() );
#define Ran(a, b) rng() % ( (b) - (a) + 1 ) + (a)

ll R = 7 + 1e9 , R1 = 19491001 , R2 = 236 , NUMTESTCASE ;
const ll NN = 10 + 1e6 ;
const double pi = acos(-1.0) ;
int di [8] = {1 , 0 , -1 , 0  , 1 , -1 , 1  , -1 } , dj [8] = {0 , 1 , 0  , -1 , 1 , -1 , -1 , 1  } ;
int m , n , Arr [NN] , Pref [NN] , Suff [NN] , Cte = 5e5 + 1 ;
int main()
{
    cin >> n ;
    forq (i , 1 , n)
        scanf("%d" , Arr + i) , Arr [i] += Cte ;

    forq (i , 1 , n)
        Suff [Arr [i]] = i ;

    qrof (i , 1 , n)
        Pref [Arr [i]] = i ;

    int Ans = 0 ;
    forr (x , NN)
        Ans = max(Ans , Suff [x] - Pref [x] + 1) ;

    cout << Ans ;
    return 0;
}