second order statistics

// ********* Assalamualaikum****** IN the name of my Almighty****:):)***
#include<bits/stdc++.h>
using namespace std;
#define suni ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define endl "\n"
#define f(i,a,b) for(int i=a;i< b;i++)
#define ff(i,a,b) for(int i= a;i>=b;i--)
#define T int t; cin >>t; while(t--)
#define vi  vector<int>
#define vll vector<long long>
#define vs vector<string>
#define vp vector<pair
#define pii pair<int,int>
#define pb push_back
#define mk make_pair
#define b(a) a.begin(),a.end()
#define rb(a) a.rbegin(),a.rend()
#define I  int
#define ll long long
#define st string
#define C char
#define mn int main()
#define fa(u,v) for(auto u:v)
mn
{
    suni;
    I n;
    cin>>n;
    set<I>s;
    I a[n];
    f(i,0,n)
    {
        cin>>a[i];
        s.insert(a[i]);
    }
    if(s.size()==1) cout<<"NO"<<endl;
    else cout<<*(++s.begin())<<endl;




   /* I n;
    cin>>n;
    vi v;
    I a[n];
    f(i,0,n)
    {
        cin>>a[i];
        v.pb(a[i]);
    }
    sort(b(v));
    I p=unique(b(v))-begin(v);
    if(p==1) cout<<"NO"<<endl;
    else cout<<v[1]<<endl;*/


}
//*******Happy Coding*******???******