#include <bits/stdc++.h>
#define ahmed_is_fast \
ios_base::sync_with_stdio(0); \
cin.tie(0); \
cout.tie(0);
#define ll long long
#define ld long double
#define cc(n) cout << n << "\n"
#define ccc(n) cout << n << ' '
#define endl "\n"
#define all(v) v.begin(), v.end()
#define mx(a, b) a = max(a, b)
#define mn(a, b) a = min(a, b)
#define mem(a, b) memset(a, b, sizeof(a))
#define f(a) a.first
#define s(a) a.second
#define lcm(a, b) (a * b) / __gcd(a, b)
#define sp(x) setprecision(x)
using namespace std;
ll freq[1000005]={0};
void ahmed()
{
ll n;
cin>>n;
ll arr[n+9];
ll brr[n+9];
ll z=0;
ll f=0;
for(ll i=0; i<n; i++)
{
cin>>arr[i];
freq[arr[i]]++;
if(freq[arr[i]]==1)
{
brr[z]=arr[i];
z++;
}
else
{
f++;
}
}
sort(brr,brr+z);
for(ll i=0; i<z; i++)
{
if(arr[i]==n-i-f)
{
cout<<arr[i]<<endl;
return;
}
if(freq[arr[i]]>1)
{
f-=freq[arr[i]];
}
}
}
bool AHMED = false;
int main()
{
ahmed_is_fast;
ll t = 1;
if (AHMED)
{
cin >> t;
}
while (t--)
{
ahmed();
}
return 0;
}
