B_Approximating_a_Constant_Range.cpp

//onAC(ALPHA) =>{Target Next ICPC ^-^}           
//  ^-^      ^-^       ^-^    ^-^     ^-^  
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp> 
using namespace std;
using namespace __gnu_pbds;


template <typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef pair<int, int> pii;
typedef pair<double, double> pdd;
typedef pair<ll, ll> pll;
typedef vector<pii> vii;
typedef vector<pll> vll;
typedef double dl;

#define PB push_back
#define F first
#define S second
#define MP make_pair
#define endl '\n'
#define all(a) (a).begin(), (a).end()
#define sz(x) (int)x.size()
#define mid(l, r) ((r + l) / 2)
#define left(node) (node * 2)
#define right(node) (node * 2 + 1)
#define mx_int_prime 999999937
#define arrin(v,n) for(int i=0;i<n;i++)cin>>v[i];
const double PI = (2.0 * acos(0.0));
const double eps = 1e-9;
const int inf = 2000000000;
const ll infLL = 9000000000000000000;
#define MOD 1000000007
const int N=1e6+123;
bitset<N> is_prime;
#define mem(a, b) memset(a, b, sizeof(a))
#define gcd(a, b) __gcd(a, b)
#define lcm(a, b) (a * (b / gcd(a, b)))
#define sqr(a) ((a) * (a))

#define optimize()                \
    ios_base::sync_with_stdio(0); \
    cin.tie(0);                   \
    cout.tie(0);
#define fraction()                \
    cout.unsetf(ios::floatfield); \
    cout.precision(10);           \
    cout.setf(ios::fixed, ios::floatfield);
#define file()                        \
    freopen("inputf.in", "r", stdin); \
    freopen("outpuft.out", "w", stdout);

typedef vector<int>::iterator vit;
typedef set<int>::iterator sit;

int dx[] = {0, 0, +1, -1};
int dy[] = {+1, -1, 0, 0};
// int dx[] = {+1, 0, -1, 0, +1, +1, -1, -1};
// int dy[] = {0, +1, 0, -1, +1, -1, +1, -1};

template <typename F, typename S>
ostream &operator<<(ostream &os, const pair<F, S> &p)
{
    return os << "(" << p.first << ", " << p.second << ")";
}

template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v)
{
    os << "{";
    for (auto it = v.begin(); it != v.end(); ++it)
    {
        if (it != v.begin())
            os << ", ";
        os << *it;
    }
    return os << "}";
}

template <typename T>
ostream &operator<<(ostream &os, const set<T> &v)
{
    os << "[";
    for (auto it = v.begin(); it != v.end(); ++it)
    {
        if (it != v.begin())
            os << ", ";
        os << *it;
    }
    return os << "]";
}

template <typename T>
ostream &operator<<(ostream &os, const multiset<T> &v)
{
    os << "[";
    for (auto it = v.begin(); it != v.end(); ++it)
    {
        if (it != v.begin())
            os << ", ";
        os << *it;
    }
    return os << "]";
}

template <typename F, typename S>
ostream &operator<<(ostream &os, const map<F, S> &v)
{
    os << "[";
    for (auto it = v.begin(); it != v.end(); ++it)
    {
        if (it != v.begin())
            os << ", ";
        os << it->first << " = " << it->second;
    }
    return os << "]";
}

#define dbg(args...)            \
    do                          \
    {                           \
        cerr << #args << " : "; \
        faltu(args);            \
    } while (0)

void faltu()
{
    cerr << endl;
}

template <typename T>
void faltu(T a[], int n)
{
    for (int i = 0; i < n; ++i)
        cerr << a[i] << ' ';
    cerr << endl;
}
void seive(){
    is_prime.set();
    is_prime[0] = is_prime[1] = false;
    for (int p = 2; p * p <= N; ++p) {
        if (is_prime[p]) {
            for (int i = p * p; i <= N; i += p)
                is_prime[i] = false;
        }
    }
}
template <typename T, typename... hello>
void faltu(T arg, const hello &...rest)
{
    cerr << arg << ' ';
    faltu(rest...);
}

ll pw(ll base , ll ex){
    ll r=1;
    base%=MOD;
    while(ex>0){
        if(ex&1) r=(r*base)%MOD;
        base=(base*base)%MOD;
        ex>>=1;
        }
        return r;
    }
    vector<ll> dijkstra(int n, vector<vector<pair<int,int>>>& g, int src) {
        const ll INF = 1e18;
        vector<ll> dist(n, INF);
        priority_queue<pair<ll,int>, vector<pair<ll,int>>, greater<pair<ll,int>>> pq;

        dist[src] = 0;
        pq.push({0, src});

        while (!pq.empty()) {
        auto [d,u] = pq.top(); pq.pop();
        if (d != dist[u]) continue;

        for (auto [v,w] : g[u]) {
            if (dist[u] + w < dist[v]) {
            dist[v] = dist[u] + w;
            pq.push({dist[v], v});
            }
        }
        }
    return dist;
    }

    vector<ll> prefix_sum(const vector<int>& a) {
        int n = a.size();
        vector<ll> p(n+1,0);
        for (int i = 1; i <= n; i++) 
            p[i] = p[i-1] + a[i-1];
        return p;
    }

    ll gcdll(ll a, ll b) {
        while (b) {
            ll t = a % b;
            a = b;
            b = t;
        }
        return a;
    }

    ll lcmll(ll a, ll b) {
        return a / gcdll(a, b) * b;
    }

    ll mod_add(ll a, ll b, ll mod) {
        a += b;
        if (a >= mod) a -= mod;
        return a;
    }

    ll mod_sub(ll a, ll b, ll mod) {
        a -= b;
        if (a < 0) a += mod;
        return a;
    }


ll MEX(const vector<ll>& arr) {
    ll n = (ll)arr.size();
    vector<char> seen(n + 1, 0); 
    for (ll x : arr) {
        if (0 <= x && x <= n) seen[(ll)x] = 1;
    }
    for (ll i = 0; i <= n; ++i) {
        if (!seen[i]) return i;
    }
    return n + 1;
}
string toBinary64(ll n) {
    string s(64, '0');  
    for (int i = 63; i >= 0; --i) {
        s[i] = (n & 1) ? '1' : '0';
        n >>= 1;
    }
    return s;
}
void solve(){

    ll n;cin>>n;
    vector<ll>v(n);
    arrin(v,n);
    map<ll,ll>mp;
    ll l=0,ans=0;
    for (int i = 0; i < n; i++)
    {
        mp[v[i]]++;
        while(!mp.empty()){
            ll mn=mp.begin()->first;
            ll mx=mp.rbegin()->first;
            if(mx-mn<=1) break;
            if (--mp[v[l]] == 0) mp.erase(v[l]);
            ++l;
        }
        ans=max(ans,i-l+1);
    }
    cout<<ans<<endl;
    
    
}
int main()
{
    optimize();
    int tc = 1;
    seive();
   // cin >> tc;
    while (tc--)
    {
       solve();
    }

    return 0;
}