#include<iostream> #include<algorithm> #include<map> using namespace std; const int N = 1e5 + 10; int a[N],s[N]; int main(){ ios::sync_with_stdio(false); cin.tie(0); int n; cin>>n; for(int i = 1; i <= n; i++)cin>>a[i]; int l = 1, r = 1, ans = -999; //map<int,int> s; //s.insert(a[l]); for(int i = 1,j = 1; i <= n ;i++){ s[a[i]]++; while(j <= i && s[a[i]] > 1){ s[a[j]]--; j++; } ans = max(ans,i - j + 1); } cout<<ans<<endl; return 0; }